I just discovered that basic race (white, black, American Indian, Asian, and Other) data at the tract level in 1990 are missing in the Philadelphia and Baltimore metropolitan areas. For other metropolitan areas I have in my data base (Boston, Chicago, Cleveland, Detroit, LA, Pittsburgh, San Francisco, St. Louis) these data are available for tracts in 1990.
I just pulled the table NP6. Race from the 1990 STF 1 - 100% Data (1990_STF1) at the census tract level. I observe 367 census tracts for Philadelphia County, 203 census tracts for Baltimore City, and 198 census tracts for Baltimore County. Could you provide more information about the dataset and table(s) you requested data for? That would help me troubleshoot your issue. You could also copy and paste the codebook that came with your dataset - that provides a lot of information about the source of the data you grabbed.
Sincerely,
Dave Van Riper
IPUMS