Correspondence, invitations, newsletters, printed materials, and related papers regarding Carss' activities as a (Farmer-Labor) U.S. representative from Minnesota's Eighth Congressional District (1919-1921, 1925-1929).

The collection consists largely of legislative issue files documenting Carss' efforts for his constituents, especially those in St. Louis, Lake, and Cook counties. There is information on the construction of the Duluth aerial lift bridge and harbor improvements; agitation for a Coast Guard station in Grand Marais; information on the progress of St. Lawrence Seaway proposals; the establishment of the Superior National Forest; individual immigration cases; and petitions to repeal wartime liquor prohibition laws (1919). Files of major significance include civil service appointments relating to federal employment in the district; military pensions for Civil War, Spanish-American War, and World War I veterans; and postmaster appointments and the construction of new post office buildings.

There are also political correspondence files containing letters from prominent Minnesota and national political figures, relating especially to the campaigns of 1924, 1926, and 1928, with a few items concerning the 1918 campaign. Also included in these files are correspondence, resolutions, and other papers from various labor organizations. A small collection of Washington office personal files contain correspondence between Carss and two of his Washington office staff: Helen Rawlings and Therese Pierson, with information on routine constituent matters and miscellaneous correspondence, including invitations. At the end of the collection is a small group of Carss' newsletters (1926-1928).