Party Leaders in the United States Congress, 1789-2009 [Updated November 25, 2008] [open pdf - 237KB]
"This report briefly describes current responsibilities and selection mechanisms for 15 House and Senate party leadership posts and provides tables with historical data, including service dates, party affiliation, and other information for each. Tables have been updated as of the report's issuance date to reflect leadership changes. The report will be updated as changes in House and Senate party leadership positions occur."
CRS Report for Congress, RL30567
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