Pursuant to a statute providing for the automatic reapportionment of seats in the United States House of Representatives (House), the Bureau of the Census (Bureau) (defendant) compiled the results of the 1990 census. Before reporting the census results to the president of the United States (defendant), the Bureau decided to allocate over 900,000 military personnel employed overseas to their home states of record. This decision resulted in both a decrease in the population of Massachusetts and an increase in the population of Washington. Secretary of Commerce Franklin (Secretary) (defendant) then reported the census results to the president. As required by the automatic-reapportionment statute, the president sent the Senate a statement of (1) the population totals for each state based on the census results and (2) the number of representatives to which each state was entitled according to a mathematical formula prescribed by Congress. Due to this reapportionment, Massachusetts (plaintiff) lost one House seat to Washington. Massachusetts and two of its citizens (plaintiffs) filed suit in federal district court against the president, the Secretary, and the Bureau, challenging the method used to count overseas federal employees for purposes of allocating House seats. The district court held that the method was an abuse of discretion under the Administrative Procedure Act (APA), 5 U.S.C. § 551 et seq. The United States Supreme Court granted certiorari to determine whether the method was reviewable under the APA.