It not only came from the fans in the stands and the opposing dugout, but also from some on his own club. Dodgers teammate Dixie Walker started an anti-Robinson petition, and during the first 37 games of the season, Robinson was hit by a pitch six times. No. 42 was also a target at first base, where runners would dig their cleats into the back of his ankle when running down the first-base line.
A's left fielder Shannon Stewart learned about Robinson's career from his dad while in grade school, but he wasn't quite sure what all of it meant at the time. As Stewart got older, though, he found out about all of the struggles that Robinson had to endure, and that made him want to wear No. 42 on Sunday in remembrance of the legendary first baseman.
"When you're 10 years old," Stewart said. "You don't really understand what he is saying, but the older you get, you start to understand more."
Introduced in 2004, Jackie Robinson Day was created to honor the enduring impact of Jackie Robinson and his legacy as the first African-American player to break the Major League color barrier. Robinson played his first Major League game at Ebbets Field on April 15, 1947, as a member of the Brooklyn Dodgers. In honor of the 50th anniversary of Robinson breaking the Major League color barrier in 1997, Robinson's uniform No. 42 was retired throughout the Major Leagues.
Robinson's memory lives on today in initiatives such as the Jackie Robinson Foundation, which was founded by Rachel Robinson in 1973 to provide education and leadership development opportunities for minority students with strong capabilities but limited financial resources, as well as Breaking Barriers, which utilizes baseball-themed activities to reinforce literacy skills, mathematics, science and social history while addressing critical issues of character development such as conflict resolution and self-esteem.
Robinson's performance on the field led not only to Civil Rights changes in sports, but also in the American society. His step onto the Ebbets Field happened before Brown vs. the Board Education and his legacy will never be forgotten.
"He really didn't take what he did for granted," Stewart said. "What he did was a good thing, him being the first, especially with what he went through. What he went through was the thing that he was most impressive."
A video tribute to Robinson was played on the scoreboard at McAfee Coliseum prior to Sunday's game, and moments of Robinson's career were also shown between innings.
Two Jackie Robinson Foundation scholars, seniors Kristin Jones from the University of California at Berkeley and Tiffany Anaerbere from Stanford University, threw out the ceremonial first pitch to Milton Bradley and Stewart. The A's Community Fund made a $5,000 donation to the Jackie Robinson Foundation, which will be used for their Leadership and Development program.
Kevin Lucas from Aptos, Calif., attended his first baseball game of the season on Sunday and said that the ceremonies for Robinson can serve as educational service for those who weren't alive when Robinson broke into the league.
"I think [Major League Baseball] should do a lot more serious stuff like this," Lucas said. "It will open up the eyes for the young people that didn't get to see the same things as their grandma and grandpa saw. Kids would be more intoned to what baseball players went through that were [African American].
"[Robinson] was just an all-around hustler," Lucas added. "It seemed to me that regardless of the stuff that was going on, he still played hard for his teammates, whether they treated him well or not."
Ryan Quinn is a contributor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.