Today in history: On Feb. 18, 2001, auto racing star Dale Earnhardt Sr. died in a crash in the final lap of the Daytona 500; he was 49. Also on this date: In 1885, Mark Twain’s “Adventures of Huckleberry Finn” was published in the U.S. for the first time. In 1930, the dwarf planet Pluto was discovered by American astronomer Clyde Tombaugh. In 1970, the “Chicago Seven” defendants were found not guilty of conspiring to incite riots at the 1968 Democratic National Convention; five were convicted