# NHGIS **URL:** https://forum.ipums.org/c/nhgis/26.md?page=2 [Latest](https://forum.ipums.org/latest.md) · [Categories](https://forum.ipums.org/categories.md) **Page:** 3 --- ## [Historical central (principal) city data](https://forum.ipums.org/t/historical-central-principal-city-data/5783)
**Author:** [@Yeonhwa\_Lee](https://forum.ipums.org/u/Yeonhwa_Lee)\ **Replies:** 3\ **Last updated:** [May 16, 2024, 2:27pm UTC](https://forum.ipums.org/t/historical-central-principal-city-data/5783 "2024-05-16T14:27:41Z")
Hello, I would like to be able to identify tracts that belonged to central cities. For more recent years (e.g., 1999, 2009, and on), it appears that I can take the OMB’s list of central / principal cities, use the place… --- ## [Projection for interior points in tabular data](https://forum.ipums.org/t/projection-for-interior-points-in-tabular-data/5883)
**Author:** [@Benjamin\_Couillard](https://forum.ipums.org/u/Benjamin_Couillard)\ **Replies:** 1\ **Last updated:** [May 14, 2024, 6:29am UTC](https://forum.ipums.org/t/projection-for-interior-points-in-tabular-data/5883 "2024-05-14T06:29:35Z")
Hello, I noticed that tabular data (eg for 1990 and 2000 census blocks) contains coordinate columns for interior points of the polygons. I am wondering what projection is being used here. I have read elsewhere (https://… --- ## [Block group crosswalk (1990-\>2010 and 2000-\>2010)](https://forum.ipums.org/t/block-group-crosswalk-1990-2010-and-2000-2010/5859)
**Author:** [@Sanghee\_Mun](https://forum.ipums.org/u/Sanghee_Mun)\ **Replies:** 2\ **Last updated:** [May 7, 2024, 2:14am UTC](https://forum.ipums.org/t/block-group-crosswalk-1990-2010-and-2000-2010/5859 "2024-05-07T02:14:57Z")
Hello, I am working on obtaining the median household income for the years 1990 and 2000, using block group data as defined by the 2010 census geography. I initially planned to collect median household income data from 1… --- ## [1940 Census data at the city level?](https://forum.ipums.org/t/1940-census-data-at-the-city-level/5856)
**Author:** [@Samantha\_Friedman](https://forum.ipums.org/u/Samantha_Friedman)\ **Replies:** 2\ **Last updated:** [May 1, 2024, 8:06pm UTC](https://forum.ipums.org/t/1940-census-data-at-the-city-level/5856 "2024-05-01T20:06:39Z")
Hi, How can I obtain characteristics at the city level using the 1940 census data? I tried to pull it at the place level from NHGIS, but there are no active data tables for this level of analysis, even though it appear… --- ## [Can census tracts from 1980, 1990, and 2000 be linked?](https://forum.ipums.org/t/can-census-tracts-from-1980-1990-and-2000-be-linked/4745)
**Author:** [@Harry\_Izatt](https://forum.ipums.org/u/Harry_Izatt)\ **Replies:** 3\ **Last updated:** [April 16, 2024, 2:01pm UTC](https://forum.ipums.org/t/can-census-tracts-from-1980-1990-and-2000-be-linked/4745 "2024-04-16T14:01:56Z")
I’m working on a project involving property values at the census tract level across decades. I have the NHGIS shapefiles for these tracts (and 2010 and 2020, though these are less important). From what I understand, cen… --- ## [Race and ethnicity in the 2010 decennial Census data](https://forum.ipums.org/t/race-and-ethnicity-in-the-2010-decennial-census-data/5791)
**Author:** [@Joseph\_Fong](https://forum.ipums.org/u/Joseph_Fong)\ **Replies:** 5\ **Last updated:** [April 11, 2024, 12:52am UTC](https://forum.ipums.org/t/race-and-ethnicity-in-the-2010-decennial-census-data/5791 "2024-04-11T00:52:15Z")
Hello, I have been trying to create a dataset of the Asian Indian-only population (only endorsed Asian Indian race/ethnicity and no others) in the U.S. using the 2010 decennial Census. I was able to find this informatio… --- ## [Housing units by number of rooms on tract level?](https://forum.ipums.org/t/housing-units-by-number-of-rooms-on-tract-level/5750)
**Author:** [@Ria\_Wilken](https://forum.ipums.org/u/Ria_Wilken)\ **Replies:** 1\ **Last updated:** [March 22, 2024, 5:50pm UTC](https://forum.ipums.org/t/housing-units-by-number-of-rooms-on-tract-level/5750 "2024-03-22T17:50:41Z")
Dear all, I am searching for housing data on the tract level or city district level in the long run. The best case would be data on housing units by the number of rooms at the city district level from 1900 to today for … --- ## [Vehicles Available by Household](https://forum.ipums.org/t/vehicles-available-by-household/5732)
**Author:** [@Ethan\_McIntosh](https://forum.ipums.org/u/Ethan_McIntosh)\ **Replies:** 2\ **Last updated:** [March 11, 2024, 12:56am UTC](https://forum.ipums.org/t/vehicles-available-by-household/5732 "2024-03-11T00:56:50Z")
I am doing an analysis of households by the number of vehicles available going back multiple decades, and I was unable to find NHGIS tables on this topic. I was able to locate some of the older data in dbf format on the … --- ## [Time Series with 2020 Geographic Integration](https://forum.ipums.org/t/time-series-with-2020-geographic-integration/4893)
**Author:** [@Peter\_Furst](https://forum.ipums.org/u/Peter_Furst)\ **Replies:** 7\ **Last updated:** [March 5, 2024, 6:48pm UTC](https://forum.ipums.org/t/time-series-with-2020-geographic-integration/4893 "2024-03-05T18:48:53Z")
Will NHGIS release time series tables with geographic integration standardized to 2020 in the next month or so? If not, I assume one should use the 2010 geographic integration and apply the 2010-2020 crosswalk. Is that c… --- ## [School districts and LEAIDs](https://forum.ipums.org/t/school-districts-and-leaids/5711)
**Author:** [@professorpat47](https://forum.ipums.org/u/professorpat47)\ **Replies:** 2\ **Last updated:** [February 29, 2024, 11:52am UTC](https://forum.ipums.org/t/school-districts-and-leaids/5711 "2024-02-29T11:52:27Z")
Are the geographic districts for elementary, secondary, or unified most similar to the LAEIDs used by the EDGE program of the census, and can you merge them together or do you need a crosswalk if one exists? --- ## [Tract-level land and water area for 1940-1960](https://forum.ipums.org/t/tract-level-land-and-water-area-for-1940-1960/5685)
**Author:** [@Yeonhwa\_Lee](https://forum.ipums.org/u/Yeonhwa_Lee)\ **Replies:** 2\ **Last updated:** [February 19, 2024, 5:17pm UTC](https://forum.ipums.org/t/tract-level-land-and-water-area-for-1940-1960/5685 "2024-02-19T17:17:35Z")
Hello, I am wondering if land and water area at the tract level (variables available as ALAND and AWATER in recent years) are available for earlier years; the years I am interested in are 1940-1960. Thank you very much… --- ## [Why does Wisconsin lack county subdivision data in 1980?](https://forum.ipums.org/t/why-does-wisconsin-lack-county-subdivision-data-in-1980/5656)
**Author:** [@John\_Johnson](https://forum.ipums.org/u/John_Johnson)\ **Replies:** 3\ **Last updated:** [February 6, 2024, 7:12pm UTC](https://forum.ipums.org/t/why-does-wisconsin-lack-county-subdivision-data-in-1980/5656 "2024-02-06T19:12:40Z")
At least some tables lack county subdivision data for the state of Wisconsin in 1980. An example is table DD5 (“Sex by Marital Status by Age”). I was surprised by this because time series table A34 includes Wisconsin cou… --- ## [Geographic crosswalk interpolation weight for adults 25 years and older](https://forum.ipums.org/t/geographic-crosswalk-interpolation-weight-for-adults-25-years-and-older/5654)
**Author:** [@Jacquelyn\_Menghrajan](https://forum.ipums.org/u/Jacquelyn_Menghrajan)\ **Replies:** 2\ **Last updated:** [February 6, 2024, 8:39am UTC](https://forum.ipums.org/t/geographic-crosswalk-interpolation-weight-for-adults-25-years-and-older/5654 "2024-02-06T08:39:40Z")
Hi! For the geographic crosswalks from block groups, are there any plans to create an interpolation weight for the adult population 25 years and older? (I’m interested in comparing educational attainment between 2015 and… --- ## [Adding a base map to census geometry in python](https://forum.ipums.org/t/adding-a-base-map-to-census-geometry-in-python/5658)
**Author:** [@Aziz\_Sunderji](https://forum.ipums.org/u/Aziz_Sunderji)\ **Replies:** 1\ **Last updated:** [February 5, 2024, 7:33pm UTC](https://forum.ipums.org/t/adding-a-base-map-to-census-geometry-in-python/5658 "2024-02-05T19:33:32Z")
Hello! I am trying to map census data (downloaded with geometry from NHGIS) in python using matplotlib and adding a basemap using contextily. Basemaps are in crs 3587, but when I convert the NHGIS geometry from its nat… --- ## [2018-2022 ACS data by congressional district](https://forum.ipums.org/t/2018-2022-acs-data-by-congressional-district/5645)
**Author:** [@JWANG](https://forum.ipums.org/u/JWANG)\ **Replies:** 3\ **Last updated:** [January 30, 2024, 7:59pm UTC](https://forum.ipums.org/t/2018-2022-acs-data-by-congressional-district/5645 "2024-01-30T19:59:54Z")
Hi, I’m wondering when 5-year 2018-2022 ACS data by congressional district (118th) will be available? The available congressional district on data selector/filter are for 116th, 115th and backwards. And no data from 5-y… --- ## [2000 to 2010 block (or other) crosswalk for Puerto Rico](https://forum.ipums.org/t/2000-to-2010-block-or-other-crosswalk-for-puerto-rico/5630)
**Author:** [@Lynn\_Rodgers](https://forum.ipums.org/u/Lynn_Rodgers)\ **Replies:** 3\ **Last updated:** [January 26, 2024, 6:42pm UTC](https://forum.ipums.org/t/2000-to-2010-block-or-other-crosswalk-for-puerto-rico/5630 "2024-01-26T18:42:29Z")
I would give my eye teeth for block (or lowest available) 2000 to 2010 crosswalk for Puerto Rico along with the same geography pop file. The current 2000 to 2010 crosswalk (which is brilliant, by the way) does not appea… --- ## [1980 Census STF3 Suppression Flags](https://forum.ipums.org/t/1980-census-stf3-suppression-flags/5616)
**Author:** [@Ryan\_Gallagher](https://forum.ipums.org/u/Ryan_Gallagher)\ **Replies:** 2\ **Last updated:** [January 18, 2024, 9:34pm UTC](https://forum.ipums.org/t/1980-census-stf3-suppression-flags/5616 "2024-01-18T21:34:56Z")
Dear NHGIS - I am working with your 1980 decennial census place-level data. However, it does not appear that suppression flags were digitized by NHGIS. Is this correct or am I missing something? Per the original Cens… --- ## [Puma vintage 2006-2010 ACS 5year](https://forum.ipums.org/t/puma-vintage-2006-2010-acs-5year/5579)
**Author:** [@watso220](https://forum.ipums.org/u/watso220)\ **Replies:** 1\ **Last updated:** [January 2, 2024, 7:02pm UTC](https://forum.ipums.org/t/puma-vintage-2006-2010-acs-5year/5579 "2024-01-02T19:02:33Z")
Is it correct that the 2006-2010 ACS 5year uses PUMA-2000 definitions but also uses TRACT-2010 definitions? It seems odd to me that the same product would blend the geography vintages. Thanks, Luke --- ## [Confirmation email](https://forum.ipums.org/t/confirmation-email/5562)
**Author:** [@Haoyu\_Wang](https://forum.ipums.org/u/Haoyu_Wang)\ **Replies:** 1\ **Last updated:** [December 19, 2023, 4:59pm UTC](https://forum.ipums.org/t/confirmation-email/5562 "2023-12-19T16:59:52Z")
I recently created an account on NHGIS using the email address hywang@mail.bnu.edu.cn. Regrettably, I have not received the confirmation email, which is hindering my ability to download data from the platform. --- ## [2010 Block Groups](https://forum.ipums.org/t/2010-block-groups/5520)
**Author:** [@SImon\_Kopecky](https://forum.ipums.org/u/SImon_Kopecky)\ **Replies:** 1\ **Last updated:** [November 8, 2023, 4:52pm UTC](https://forum.ipums.org/t/2010-block-groups/5520 "2023-11-08T16:52:02Z")
Why can I not view 2010 block group data for household and family income? --- ## [Hispanic persons by race in 1970 tracts](https://forum.ipums.org/t/hispanic-persons-by-race-in-1970-tracts/5476)
**Author:** [@Ethan\_McIntosh](https://forum.ipums.org/u/Ethan_McIntosh)\ **Replies:** 1\ **Last updated:** [October 3, 2023, 4:04pm UTC](https://forum.ipums.org/t/hispanic-persons-by-race-in-1970-tracts/5476 "2023-10-03T16:04:15Z")
I have pulled tract-level 1970 data on sex by age (NT17) with a race/ethnicity breakdown (all races, white, black, and Hispanic). From this set of variables, I am interested in generating mutually exclusive race/ethnicit… --- ## [1980 Census Age Data](https://forum.ipums.org/t/1980-census-age-data/5362)
**Author:** [@Ashlynn\_Wimer](https://forum.ipums.org/u/Ashlynn_Wimer)\ **Replies:** 5\ **Last updated:** [September 25, 2023, 1:05pm UTC](https://forum.ipums.org/t/1980-census-age-data/5362 "2023-09-25T13:05:13Z")
I’m doing an analysis involving tract level data from the 1980 census, and I noticed a weird discrepancy between table NT10A (age of all persons at tract level in 1980) and tables NT7, NT8, and NT1A (respectively race, S… --- ## [Number of unique blocks in the Crosswalk file vs. 1990 STF1](https://forum.ipums.org/t/number-of-unique-blocks-in-the-crosswalk-file-vs-1990-stf1/5426)
**Author:** [@Seunghoon\_Lee](https://forum.ipums.org/u/Seunghoon_Lee)\ **Replies:** 2\ **Last updated:** [August 28, 2023, 7:29pm UTC](https://forum.ipums.org/t/number-of-unique-blocks-in-the-crosswalk-file-vs-1990-stf1/5426 "2023-08-28T19:29:12Z")
Hi, I found that there is a substantial difference in the number of unique blocks in the block-level crosswalk file (e.g., Blocks → Blocks: GISJOIN Identifiers for 1990 to 2010) and the decennial census. To be concrete… --- ## [Example API Export With ACS IPUMS](https://forum.ipums.org/t/example-api-export-with-acs-ipums/5427)
**Author:** [@Joseph\_Konan](https://forum.ipums.org/u/Joseph_Konan)\ **Replies:** 1\ **Last updated:** [August 28, 2023, 4:28pm UTC](https://forum.ipums.org/t/example-api-export-with-acs-ipums/5427 "2023-08-28T16:28:45Z")
I would like to use the IPUMS API to make a 1-year ACS query that yields the identical result of the Data Extractor. For example, when selecting all variables in the Data Extractor for the 1-year ACS 2021 (2021\_ACS1), w… --- ## [Block-group-level data on (a) Single vs. multi housing units, and (b) home ownership](https://forum.ipums.org/t/block-group-level-data-on-a-single-vs-multi-housing-units-and-b-home-ownership/5423)
**Author:** [@Dean\_Rosenblum](https://forum.ipums.org/u/Dean_Rosenblum)\ **Replies:** 2\ **Last updated:** [August 25, 2023, 5:51pm UTC](https://forum.ipums.org/t/block-group-level-data-on-a-single-vs-multi-housing-units-and-b-home-ownership/5423 "2023-08-25T17:51:34Z")
Hi all, I’m looking for census block group-level data that breaks out the n of housing units (readily available) into: (a) single vs. multi-family homes, and (b) owner occupied vs. renter occupied, And, ideally, with… --- ## [Best match data file?](https://forum.ipums.org/t/best-match-data-file/5399)
**Author:** [@Erin\_Campbell](https://forum.ipums.org/u/Erin_Campbell)\ **Replies:** 1\ **Last updated:** [August 8, 2023, 3:27pm UTC](https://forum.ipums.org/t/best-match-data-file/5399 "2023-08-08T15:27:48Z")
I have information about location at a city + state level from present day back to the 1980s. What is the best way to match city + state to a polygon back in time? I’ve experimented with Place boundaries, but I’m intere… --- ## [Deleted post — please disregard](https://forum.ipums.org/t/deleted-post-please-disregard/5390)
**Author:** [@Emiliano\_Harris](https://forum.ipums.org/u/Emiliano_Harris)\ **Replies:** 0\ **Last updated:** [July 27, 2023, 10:08pm UTC](https://forum.ipums.org/t/deleted-post-please-disregard/5390 "2023-07-27T22:08:40Z")
Hello, I’m wondering if the 1940 Census tract occupational group counts are just for the civilian population, or if they include members of the Armed Forces? I know that these counts are restricted to employed civilian… --- ## [1970-1980 Place boundary files](https://forum.ipums.org/t/1970-1980-place-boundary-files/4418)
**Author:** [@Carl\_LA](https://forum.ipums.org/u/Carl_LA)\ **Replies:** 6\ **Last updated:** [July 24, 2023, 4:19pm UTC](https://forum.ipums.org/t/1970-1980-place-boundary-files/4418 "2023-07-24T16:19:58Z")
Dear NHGIS team, I seem to remember that you were working on creating GIS boundary files for 1970 places. Is that correct? If so is there a timeline available. Alternatively, will the forthcoming 1970 block geography hav… --- ## [Clarity on Tract Crosswalk Calculations](https://forum.ipums.org/t/clarity-on-tract-crosswalk-calculations/5360)
**Author:** [@Darrell\_Owens](https://forum.ipums.org/u/Darrell_Owens)\ **Replies:** 1\ **Last updated:** [June 30, 2023, 3:26pm UTC](https://forum.ipums.org/t/clarity-on-tract-crosswalk-calculations/5360 "2023-06-30T15:26:12Z")
I’m trying to calculate the net difference in population from a 2010 tract to a 2020 tract. I’m aware of all the difficulties with accuracy, but I want to be positive I’m following the methodology of the crosswalks corre… --- ## [Too many missing values in median Black household income](https://forum.ipums.org/t/too-many-missing-values-in-median-black-household-income/5344)
**Author:** [@JKim](https://forum.ipums.org/u/JKim)\ **Replies:** 1\ **Last updated:** [June 23, 2023, 8:24pm UTC](https://forum.ipums.org/t/too-many-missing-values-in-median-black-household-income/5344 "2023-06-23T20:24:18Z")
Hi. I’m looking at median Black household income of each Census tract from the source table B19013B. I’m looking at two time periods, 2008-2012 and 2015-2019. However, I’m seeing too many missing values of more than 30,0… [Previous page](https://forum.ipums.org/c/nhgis/26.md?page=1) [Next page](https://forum.ipums.org/c/nhgis/26.md?page=3)