Correspondence, diaries, journals, notebooks, family papers, military papers, drawings, maps, plans, scrapbooks, photographs, sketches and studies, and other papers relating primarily to Meigs's work in the U.S. Army Corps of Engineers, his service as quartermaster general during the Civil War, and family matters. supervising construction in Maryland and Washington, D.C., on the Washington Aqueduct, additions to the U.S. Capitol, and the Pension Office building. Also includes material relating to the death of his son John Rodgers Meigs, and travels in Europe and Texas. Family papers include correspondence of Meig's wife, Louisa Rodgers Meigs, his father, Charles D. Meigs, and his brother, Emlen, and the papers of his son Montgomery Meigs (1847-1931).

Correspondents include Spencer Fullerton Baird, James Buchanan, Bernhard Ernst von Bülow, Ambrose Everett Burnside, Simon Cameron, Adolph Cluss, Jefferson Davis, John B. Floyd, Horace Greeley, Joseph Henry, Joseph Holt, Charles P. Manning, George Brinton McClellan, Helmuth graf von Moltke, David Dixon Porter, Frederick William Seward, William Henry Seward, William T. Sherman, Edwin McMasters Stanton, and Joseph Gilbert Totten.