Correspondence, legal briefs, financial data, docket book, printed matter, file of reports, opinions, and briefs arranged by case name, and other papers relating to McLean's service as U.S. postmaster general and U.S. Supreme Court justice. Also contains material from his service as commissioner of the U.S. General Land Office. Includes his notes on arguments made before the U.S. Supreme Court in 1830, including cases argued by John MacPherson Berrien, Francis Scott Key, David Bayard Ogden, Roger Brooke Taney, Daniel Webster, and William Wirt. Subjects include the history of Washington, D.C.; Cincinnati, Ohio, Ohio state, and national politics; Indian affairs; international relations; presidential politics; secession; slavery; and the Whig Party. Correspondents include Caleb Atwater, James Buchanan, John C. Calhoun, Salmon P. Chase, John M. Clayton, Thomas Corwin, George Mifflin Dallas, John Henry Eaton, Ninian Edwards, Edward Everett, Thomas Ewing, Duff Green, Isaac Hill, Samuel D. Ingham, Richard M. Johnson, Henry Lee, James Madison, Duncan McArthur, James Monroe, Richard Peters, William C. Rives, Richard Rush, Winfield Scott, Thomas Sergeant, William Henry Seward, Edwin McMasters Stanton, Joseph Story, Charles Sumner, Roger Brooke Taney, John Tyler, Henry Dana Ward, Daniel Webster, Thurlow Weed, and James Whitcomb.