How come my .dat file has one column and all rows contain the same numerical value? I should have 16 variables
The .dat file (when properly unzipped with a decompression software) is a fixed-width data file. Also available for download on the Download and Revise Extracts page are command files associated with various statistical software (SPSS, SAS, Stata, and R). Using a command file to read in the .dat file into your preferred statistical software will provide you with a data set with distinct variables. More specific details about downloading and opening IPUMS data can be found here.