Selections and extracts from Irvine manuscripts, 1776-1834, copied by Draper in 1849 from originals loaned to him by Irvine's grandson, William A. Irvine of Warren County, Pennsylvania. The majority of these copies were later published by Consul W. Butterfield in Washington-Irvine Correspondence (Madison, 1882). The few letters written after 1802 were addressed to Callender Irvine but relate to his father's military service and character.

The topics are prefaced by detailed chronological and subject indexes by Draper in which nearly 150 individual names are listed; those featured most frequently include John Armstrong, (1717-1795) and his son of the same name (1758-1843), Stephen Bayard, Samuel Brady (for whom there are eight pages of index), Daniel Brodhead, Richard Butler, William Butler, James Chambers, George Rogers Clark, Edward Cook, Lord Cornwallis, Thomas Craig, Isaac Craig, William Crawford, David Duncan, John Evans, John Finley, John Gibson, and David Grier. Also included are Richard Hampton, Josiah Harmar, Samuel Hay, Simon Kenton, James Marshal, John Rose (Baron Rosenthal), David Shepherd, Thomas Sumter, Anthony Wayne, David Williamson, and David Zeigler.

Copies of Irvine's correspondence, 1781-1783, while he was commanding general at Fort Pitt. These transcripts were made by Butterfield and were sent to Draper after the publication of Butterfield's book. These letters were neither included in that publication nor indexed. Although most of the letters deal with border defense and the great majority of the writers were military officers, there are more than fifteen personal letters written by Irvine to his wife; these pertain to family health, business affairs, servants, and the children's education.

Writers of letters to Irvine were Joseph Beckett, Thomas Buchanan, Richard Butler, William Butler, John Byers, Charles Campbell, Thomas Clingman, Joshua Davidson, John David, David Duncan, M. Everly, Charles Foreman, Hugh Goudy, Robert Hanna, Peter Harkcom, Christopher Hays, Moses Hazen, Michael Huffnagle, John Irwin, and Thomas Irwin. Also included were Richard Johnson, M. Lacassagne, William Love, Alexander McClean, William McCleary, David McKee, John Marshall, John Montgomery, Thomas Moore, William Neill, James Potter, John Pumroy, Henry Rhoads, Matthew Ritchie, John Rose (Baron Rosenthal), Arthur St. Clair, Samuel Sample, David Shepherd, Devereaux Smith, Dennis Springer, William Trent, George Vallandigham, David Vance, Samuel Wilson, and Antoine Felix Wuibert. A few letters written by Irvine were addressed to Duncan, Huffnagle, McCleary, Smith, and Trent. Bound among the copies is one original letter (May 1782) written to Irvine by William Crawford reporting on his difficulties with the volunteers in crossing the Ohio River.