Why extract returns multiple files even though one variable, one year, one dataset?


I see that a variation of this question was answer at Why do I receive so many data files in my downloaded zipped file?, where it was stated, “A tabular data file is returned for each dataset, geographic level, and year for which tables are selected. If you only downloaded county level data for one year and from one dataset, you will only receive one data file.”

However, I am having this issue even though I submitted an extract with one geographic level and one year. For instance, I submitted an extract with the following variables at the county-level for the year 1980:

  • NT91A Poverty Status in 1979
  • NT48A Years of School Completed
  • NT9A Persons of Spanish Origin
  • NT1A Persons
  • NT10A Age
  • NT55A Sex by Labor Force Status
  • NT33 Nativity and Place of Birth
  • NT65 Industry
  • NT12 Race
    This was returned as 2 .xls files rather than 1 .xls file with all of the variables.

I don’t think this is a file size issue because the files for 1980 have 106 columns total (55 variables in one and 51 variables in the other) whereas a similar extract I submitedt for the ACS 5 year estimates for 2012 - 2016 returns all of the variables in one dataset with 602 columns.



Although the tables you requested are for a single year and single geographic level, they come from two NHGIS datasets: 1980 STF1 (the main source of full-count short-form 1980 census data) and 1980 STF3 (the main source of sample-based long-form 1980 census data).

As the text you quoted states: a separate data file is returned for each dataset.

When you’re selecting tables in NHGIS, you can see which dataset each table comes from in the “Year - Dataset” column.

There’s also a general overview of NHGIS datasets on the NHGIS website.