April 21st has witnessed several notable moments in the history of Celtic Football Club. In 1906, Celtic, already champions, concluded their league season with a 1-0 victory over Hearts at Celtic Park, thanks to a goal from Jimmy Quinn. Fast forward to 1951, Celtic won the Scottish Cup for the 16th time, defeating Motherwell 1-0 in front of a record crowd of 131,943 at Hampden Park, with John McPhail scoring the decisive goal. However, 1956 brought disappointment as Celtic lost 1-3 to Hearts in the Scottish Cup final, despite Mike Haughney scoring their only goal. In 1969, a 2-2 draw against Kilmarnock secured the Scottish League Championship for Celtic, highlighted by a last-minute equalizer from Tommy Gemmell. Lastly, in 1982, Celtic edged closer to the league title with a 3-1 win over Dundee United, where George McCluskey scored twice. These moments reflect the highs and lows of Celtic's storied history.