How it unfolded
The day Branch Rickey's two-year plan went live. Robinson wore No. 42, played first base and batted second — ending sixty years of MLB's colour line on the spot. The game itself was ordinary: Robinson went 0-for-3 with a sacrifice bunt. In the seventh another bunt and a Braves first baseman's throwing error put him on; he reached third as the defence unravelled and scored the decisive run on a subsequent double. Brooklyn won 5–3. More than half of the 26,623 crowd was Black. Robinson endured organised jeers, death threats and spiked tags on the road; Phillies manager Ben Chapman's racist abuse only hardened Dodgers teammates. He hit .297 with 12 home runs and a league-leading 29 steals for Rookie of the Year; Brooklyn won the pennant.
Why it still matters
No single game in baseball history had larger consequences. The debut cracked racial segregation in American pro sport and was a nationally broadcast integration before Brown v. Board and the Montgomery bus boycott. Inside baseball the talent pool widened overnight and helped drive National League dominance for two decades; No. 42 was retired league-wide in 1997.