APA (7th ed.) Citation

Wilson, H., Barton, W. E., King, P., & William E. Barton Collection of Lincolniana. (1861). Letter: Washington, D.C., to William Henry Seward, n.p.

Chicago Style (17th ed.) Citation

Wilson, Henry, William E. Barton, Preston King, and William E. Barton Collection of Lincolniana. Letter: Washington, D.C., to William Henry Seward, N.p. 1861.

MLA (8th ed.) Citation

Wilson, Henry, et al. Letter: Washington, D.C., to William Henry Seward, N.p. 1861.