Short answers, pulled from the story.
Oklahoma comes from two Choctaw words: okla, meaning 'people', and humma, meaning 'red'. Choctaw Nation Chief Allen Wright proposed the name in 1865 during treaty negotiations with the federal government.
The Tulsa race massacre occurred in 1921, when White mobs attacked Black residents in the Greenwood district of Tulsa. Sixteen hours of rioting destroyed 35 city blocks, caused an estimated $1.8 million in property damage, and left an estimated death toll of between 75 and 300 people.
Oklahoma became the 46th state on the 16th of November 1907, when President Theodore Roosevelt issued Presidential Proclamation no. 780. Congress had authorized the path to statehood on the 16th of June 1906.
The nickname comes from settlers who crossed into formerly tribal lands before the official start of the Land Rush of 1889 and subsequent land rushes, breaking the rules by going 'sooner'. The term eventually became Oklahoma's official state nickname.
On the 19th of April, 1995, Timothy McVeigh detonated a large explosive device outside the Alfred P. Murrah Federal Building in Oklahoma City, killing 168 people, including 19 children. It remains the most destructive act of domestic terrorism in American history. McVeigh was executed by the federal government on the 11th of June 2001.
On the 9th of July 2020, the U.S. Supreme Court ruled in McGirt v. Oklahoma that the reservations of the Five Tribes, comprising much of eastern Oklahoma, had never been disestablished by Congress and thus remain 'Indian Country' for the purposes of criminal law.