The Emancipation Proclamation goes into effect. It aims to free people in slavery in parts of seceded states that fell outside of the Union. It did not impact Missouri slaveholders, according to a history from the Missouri Secretary of State. This 1864 caricature by Adalbert Volck shows Lincoln writing the proclamation.

Photo credit: Adalbert Volck via Library of Congress https://www.loc.gov/resource/rbc0001.2006gen10014/?r=-0.142,0.488,0.349,0.17,0