John Wesley Glasscock was an American shortstop in Major League Baseball who played for several teams from 1879 to 1895. Nicknamed "Pebbly Jack", he was the top player at his position in the 1880s during the sport's bare-handed era. He led the National League in fielding percentage seven times and in assists six times; he was the only shortstop to lead in fielding percentage and total chances in a season three different times until Luis Aparicio matched him. Ozzie Smith eventually surpassed Glasscock's marks in the 1980s; Glasscock also led the NL in double plays four times and in putouts twice. He won the 1890 batting title with a .336 average for the New York Giants and led the league in hits twice; in his final season he became the sixth major league player to make 2,000 hits. He was the first player to appear in over 600 games as a shortstop, and ended his career with major league records for games (1,628), putouts (2,821), assists (5,630), total chances (9,283), double plays (620) and fielding percentage (.910) at the position. When he retired he ranked fifth in major league history in games (1,736) and at bats (7,030), seventh in total bases (2,630) and eighth in doubles (313).

The following are the baseball events of the year 1890 throughout the world.