North America 1862: Battle of Antietam
Having established naval supremacy, Union forces landed on the Virginia peninsula and advanced on Richmond, only to be smashed by Confederate General Robert E. Lee in the Seven Days Battles. Lee followed up his victory with an invasion of Maryland, but was brought to a halt at the Battle of Antietam/Sharpsburg, the bloodiest single-day battle in American history. Antietam ended the threat to Washington and gave US President Abraham Lincoln confidence to issue the Emancipation Proclamation, officially ending slavery in the Confederacy.
5 May 1862 French repulsed at Puebla▲
The Mexican Army defeated the French offensive on Puebla in an action later celebrated as Cinco de Mayo.
12 May 1862 British Honduras formed▲
The British Settlement of Belize in the Bay of Honduras became the Colony of British Honduras.
25 Jun–1 Jul 1862 Seven Days Battles▲
Confederate troops under Robert E. Lee defeated George McClellan's Union Army of the Potomac near Richmond, Virginia, forcing it to retreat back down the Virginia Peninsula.
19 Jul–1 Sep 1862 Northern Virginia Campaign▲
Confederates under Robert E. Lee moved north toward Washington D.C., defeating John Pope's Union forces in northern Virginia.
17 Aug–26 Dec 1862 Dakota War▲
The United States crushed an eastern Sioux/Dakota uprising in southwest Minnesota.
17 Sep 1862 Battle of Antietam▲
Following his victory at the Seven Days Battles, Confederate General Robert E. Lee sought to bring the war to the Union itself and provoke an uprising in the pro-slavery but loyalist states of Maryland and Kentucky. However, Lee was not welcomed by Marylanders, and Union forces under George McClellan attacked his army near Sharpsburg, Maryland, leading to heavy casualties on both sides and momentarily scuttling Lee's ambitions to invade the north.