IP history: On this day (21 Feb.) in 1842, the first U.S. patent for the sewing machine is granted. (Charles Fredrick Wiesenthal, a German-born engineer working in England, was awarded the first British patent in 1755 for a mechanical device to aid the art of sewing.)
Military history: On this day (21 Feb.) in 1808, Russian troops invade Sweden at Abborfors in eastern Finland, thus beginning the Finnish War. Sweden will lose the eastern half of the country (i.e. Finland) to Russia. (Sound familiar?)
Sports history: On this day (21 Feb.) in 1948, NASCAR is created at the Ebony Bar of the Streamline Hotel (pictured below) in Daytona Beach, Florida.
prior probability 