Slavery was an extremely divisive issue in American history, and, as it turns out, it was the reason that Oklahoma has a panhandle.
Early in its evolution, the Republic of Texas stretched much further north than it does today. When it entered the Union in 1846, Texas chose to continue to permit slavery within its borders. But the Missouri Compromise of 1820 had declared that no state above the 36° 30’ mark could hold slaves. Faced with a dilemma, Texas decided to cut off a large chunk of its northern territory in order to continue to indulge in slave ownership.
By chopping off its northern border to the 36° 30’ line, a large chunk of land was now available to be divided into other states. When the Missouri Compromise was later replaced by the Kansas-Nebraska Act, Congress set the southern border of Kansas at 37° , which meant that a strip of orphan territory was created.
Congress eventually made the decision to attach that orphan strip to Oklahoma, and thus the panhandle was born.