Fair Representation: Appendix B
Representative Populations and Apportionments for Twenty-Two United States Census,
1791—2000:
http://www.thirty-thousand.org/data/Balinski_Apportionment.xls
(right-button click to download)

Notes on Balinski & Young’s “Proposition 3.8”
TTO Supplement Explaining the Proposition stated on Page 175 of Fair Representation.
http://www.thirty-thousand.org/data/Balinksi_Prop3-8.xls
(right-button click to download)

The House of Representatives Apportionment Formula: An Analysis of Proposals for Change and Their Impact on States
CRS Report for Congress; August 10, 2001 (#RL31074):
http://www.thirty-thousand.org/documents/CRS_AUG2001.pdf
(right-button click to download)
 
Supplement: Alternate Methods for Measuring Equality of District Sizes
TTO Supplemental Analysis of Table 4 (page CRS-20)
http://www.thirty-thousand.org/documents/TTO_CRS_RL31074.pdf
(right-button click to download)
 

Population Base for Apportionment: 1790-2000
Professor Margo J. Anderson's resource page provides a wealth of information:
http://www.uwm.edu/~margo/

In particular, http://www.uwm.edu/~margo/apport/datasets.htm provides a spreadsheet containing the population values used for apportionment.

U.S. Census Bureau Congressional Apportionment
http://www.census.gov/population/www/censusdata/apportionment/index.html