Delaware's legislature voted unanimously against seceding from the Union, becoming the first Southern-leaning slave state to formally reject the Confederacy.

Georgia became the fifth state to secede from the United States, voting 208 to 89 to leave the Union and join the emerging Confederacy.

Kansas became the 34th U.S. state, entering as a free state after years of violent conflict known as "Bleeding Kansas."

James Clerk Maxwell presented the first durable color photograph, using three black-and-white images shot through red, green, and blue filters.

The Confederacy's peace commissioners, sent to negotiate with Washington over federal properties like Fort Sumter, were informed the Lincoln administration would not formally receive them.

Victor Emmanuel II was declared King of a unified Italy, capping decades of struggle to merge the peninsula's fractured states into one nation.

Confederate General P.G.T. Beauregard demands the surrender of Fort Sumter in Charleston Harbor, setting the stage for the Civil War's opening shots the next day.

Confederate batteries opened fire on Fort Sumter in Charleston Harbor, igniting the first shots of the American Civil War.

As the American Civil War erupted, Louisiana's Confederate militia forces organized and moved to secure New Orleans and the Mississippi River in the war's earliest weeks.

Confederate forces routed Union troops near Manassas, Virginia, in the Civil War's first major land battle, shattering illusions of a short, bloodless conflict.

Lincoln issued the preliminary Emancipation Proclamation, warning that enslaved people in rebellious states would be freed on January 1, 1863.

Federal naval forces press their campaign to control the Mississippi River system, a crucial theater where Union gunboats fought to strangle Confederate supply lines.