o.k. - the story
O.k. is the abbreviation of okay. However, the shortform o.k. existed before okay which means that the long form was derived from the shortform. Does that make sense. Not really, as long we don't dig out out the history of o.k..
Friedrich Wilhelm von Steuben, born on September 17, 1730, in Magdeburg, Germany, began his military career at age 17 and was promoted to General of the Prussia Army in the early second half of the 18th century.
Experienced in several wars Von Steuben went to America in 1777. At the request of General George Washington he soon led and trained the Continental Army. His great tactical experience he gathered as officer of the Prussian army and the discipline lessons he taught the American troops where valuable and helped eventually to win the war.
Wilhelm von Steuben had difficulties to catch up with his English knowledge and when he confirmed correspondence he liked to state: "all correct" but what he wrote was "oll korrekt". That was spelled like he knew it from German language. Later he simply used the shortform: o.k.
However, o.k. was invented and everyone in the army knew the meaning, later the whole nation, then the whole world.