Can I extract the total population of a specific racial/ethnic group within a specific city?

I have figures from the 2010 and 2000 ACS from American FactFinder and the totals I see here for the same years are much smaller. Is there anything I am doing wrong?? The variables I select are city, year, race (where applicable) and ancestry (where applicable). Thanks in advance!

While your estimates from the IPUMS data may differ, I’m not aware of any reason why your estimates should be substantially and systematically smaller. Please note that we use the PUMA identifier to create the CITY varialble in the 2005-onward ACS, and we base this on the city boundaries as they were defined in 2000. Please see the CITY comparability tab for more details, and feel free to let us know if you still are running into issues.