This base is from a Toronto Blue Jays home game at Exhibition Stadium honouring Jackie Robinson. The base was autographed by Jimy Williams. Williams was the manager of the Toronto Blue Jays from 1986-1989. Jackie Robinson Day has been celebrated in Major League Baseball annually on April 15e since 2004. Prior to this, there was no set day each year to honour Jackie Robinson. Since this base is from a Jackie Robinson Day game in the late 1980s, it might not have been used on April 15th.