1975 Frank Robinson debuted as the first African American baseball manager (Cleveland beat New York 5-3). As player/manager, he also hit a homerun in his first at bat. From the article:
"Frank Robinson blazed trail for managers
Part of the INSIDE PITCH series
Written by: Craig Muder
Exactly one year earlier, Henry Aaron broke the game's most hallowed record.
But on April 8, 1975, Frank Robinson broke new ground in baseball's quest to truly become the National Pastime.
Robinson, hitting second for the Cleveland Indians as their new player-manager, crushed a first-inning pitch from Doc Medich for a home run to power the Indians past the New York Yankees, 5-3, on Opening Day. It was Robinson's 575th career home run in a career that was already destined to land him a place in the Hall of Fame. But this game was about more than excellence on the field for Robinson.
Never before had an African-American man been a full-time big league manager.
"It was a great moment, but you had to wait 'til the end, 'til the game was over," Robinson told The New York Times about the home run, which brought a thunderous ovation from the 56,204 fans at Cleveland Stadium. "Now, it's even more gratifying."
Robinson played in just 49 games with the Indians that year, hitting eight more home runs. But under his leadership, Cleveland went 79-80 – a 3 1/2-game improvement from the year before.
In 1976, his last season as an active player, Robinson led the Tribe to its first winning season in eight years.
But following a slow start in 1977, Robinson was dismissed.
He went on to manage the San Francisco Giants – where he became the first African-American manager in National League history in 1981 – Baltimore Orioles and Montreal Expos/Washington Nationals, winning 1,065 big league games as a manager.
In 1982, while leading the surprising Giants to 87 wins, he was enshrined at the Baseball Hall of Fame along with Aaron, who also retired following the 1976 season.
Robinson finished his playing career with 586 home runs, 1,812 RBIs, a .294 batting average, two Most Valuable Player Awards, the 1966 American League Triple Crown and two World Series titles with the Orioles."