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Key facts about the Battle of Oak Grove, also known as the Battle of French's Field and the Battle of King's School House.

Fought on June 25, 1862, the Battle of Oak Grove, also known as the Battle of French's Field and the Battle of King's School House, was the first engagement of the Seven Days Battles during the Peninsula Campaign.

Robert Ogden was a politician from New Jersey. He is significant because he participated in the Stamp Act Congress.

The Ohio Company was a company formed to buy land in the Ohio Country for the purpose of settling the region and establishing trade with Native American Indian tribes. The company played a role in starting the French and Indian War.

Key facts about the Battle of Okolona.

The Battle of Okolona was the climax of a failed Union expedition led by Brigadier General William Sooy Smith during the Meridian Campaign in February 1864.

Edson B. Olds was a Copperhead leader and three-term U.S. Congressman from Ohio. In 1862, federal officials arrested and imprisoned Olds for disloyalty.

Key facts about Edson B. Olds, a Copperhead leader and three-term U.S. Congressman who federal officials arrested and imprisoned for disloyalty during the Civil War.

Facts about the Olive Branch Petition, including dates, committee members. and more interesting details you might not know. This fact sheet provides a quick overview of the letter and is for kids doing research and students preparing for the AP U.S. History (APUSH) exam.

The Olive Branch Petition was a letter sent to King George III of England from the Second Continental Congress, attempting to avoid war with Great Britain in the American colonies.

A prominent Union general officer, Emerson Opdycke played significant roles at the Battle of Chattanooga and the Battle of Franklin.

Key facts about Emerson Opdycke, a prominent Union general officer who played significant roles at the Battle of Chattanooga and the Battle of Franklin.

Key facts about the Battle of Opequon, also known as the Third Battle of Winchester.

Fought on the morning of September 19, 1864, between Philip Sheridan's Army of the Shenandoah and Jubal Early's Army of the Valley, the Battle of Opequon, also known as the Battle of Third Winchester, was the bloodiest engagement of the Shenandoah Valley Campaign of 1864.

Key facts about the Battle of Orchard Knob.

Fought on November 23, 1863, the Battle of Orchard Knob was the first engagement of Major General Ulysses S. Grant’s breakout from Confederate General Braxton Bragg’s siege of Chattanooga.

A career United States Army officer, Edward O.C. Ord played major leadership roles in both theaters of the American Civil War and as commander of the Department of the Ohio at the conclusion of hostilities.

Key facts about Edward O.C. Ord, a career United States Army officer who played major leadership roles in both theaters of the American Civil War and as commander of the Department of the Ohio at the conclusion of hostilities.

On May 24, 1861, Brigadier General Joseph E. Johnston issued an unnumbered order announcing that he had assume command of the Confederate forces in the vicinity of Harpers Ferry, Virginia, as ordered by the secretary of war.