Cite

The gold pen used by Lincoln to sign the Emancipation Proclamation in the Executive Mansion, Washington, D.C., 1863 Jan 1

MLA

Lincoln, Abraham, 1809-1865. The gold pen used by Lincoln to sign the Emancipation Proclamation in the Executive Mansion, Washington, D.C., 1863 Jan 1. Box 3, folder 24. n.d.. https://collections.library.yale.edu/catalog/2005512.

APA, 6th edition

Lincoln, Abraham, 1809-1865. (["Box 3, folder 24"])(n.d.)[The gold pen used by Lincoln to sign the Emancipation Proclamation in the Executive Mansion, Washington, D.C., 1863 Jan 1]. https://collections.library.yale.edu/catalog/2005512.