"You know, for me, it was an initial shock because I had no clue that I was going to be traded," Boldin told ESPN producer Ashly Robinson, who is in Africa to document his trip with fellow NFL receivers Larry Fitzgerald and Roddy White. They are working with Oxfam to restore farmland in Senegal.
"... It was shocking at first ... but I mean it, for me, it is also a good thing. ... When I look at the organization and what they're about ... and as a football team, the talent that they have ... I think it's good, a good place for me to be," he told ESPN.
Boldin said he learned about the deal when he got off the plane in Africa and saw that he had received several texts congratulating him on the trade.
In Baltimore, his coach was John Harbaugh; his coach in San Francisco will be his former coach's brother, Jim Harbaugh. He told ESPN that he sees the 49ers as "a team that's very close, a team that I feel like is on the cusp ... and hopefully I can go there and help them achieve the goals they have in mind."
Boldin also posted a message of thanks to Ravens fans through his Twitter account Tuesday.
"I would like thank the Ravens fans for their incredible support for myself and my family throughout my years in Baltimore," he wrote. "I am grateful in getting to know you and will miss what I call home.
"I thought this was the last stop of my career but regardless of the circumstances I came here to win a Championship and in February we came home Champions."
The Ravens will receive a sixth-round draft choice in the trade, which is contingent on Boldin passing a physical when he returns from Africa.
"We are excited to add Anquan to our roster," 49ers general manager Trent Baalke said in a statement. "He is a highly competitive and productive player with strong leadership qualities that will be a welcome addition to our team and community."
Ravens general manager Ozzie Newsome addressed the difficult decision he had to make in trading away Boldin.
"Managing and assembling your roster is difficult and among the most important things we do," Newsome said in a statement. "It is not always pleasant, and in the case of Anquan, it is unpleasant.
"We know he can still play at a high level. What he has done in his three seasons with us goes well beyond the numbers, and his numbers are very good. He fit in as a Raven from Day 1. His leadership, just by the way he played and prepared, was a powerful force for us. And when we needed the tough catch in important times, he made those. Look at his production in our Super Bowl run. He stepped up in a big way. When he wasn't targeted, or when we weren't passing, his blocking was outstanding. We all thank 'Q' for what he did for the Ravens over the last three years."
According to ESPN Stats & Information, Monday's trade of Boldin to the 49ers is the first trade between teams that met in the previous Super Bowl since the St. Louis Rams traded both Kole Ayi and Grant Williams (in separate trades) to the New England Patriots for draft picks in the 2002 offseason. Williams played in Super Bowl XXXVI for the Rams. Ayi did not.
Ravens quarterback Joe Flacco reacted with disappointment when he learned of the trade Monday.
"Anquan was a great receiver for myself and for our football team," said Flacco, who signed a six-year, $120.6 million deal with the Ravens last week. "It's sad to see a guy like that go, but at the same time, you want what's best for him and you just wish him the best of luck.
"Anquan was a big part of this football team, a big part of this offense. He's one of the many reasons we won the Super Bowl this year."
Boldin also was a strong voice in the locker room and a teacher to second-year wide receiver Torrey Smith, who will likely become Flacco's top target in 2013.
"Definitely shocked," Smith said of the deal. "You lose a great guy, a great leader. A mentor. All of that."
Smith was more concerned about being in the huddle without Boldin than taking over as the Ravens' top pass-catching threat.
"It's not so much about football when you lose someone like that, someone you love like a brother and would do anything for you," Smith said.
While Smith was upset, Boldin's potential new quarterback, Colin Kaepernick, was excited by the trade when he spoke with ESPN on Monday.
"If it's true, it's a great trade," Kaepernick told ESPN. "We're happy to have him. Having a playmaker like that at receiver is something you always want. It's another weapon for our offense and our team."
Kaepernick added that he thought the Niners were getting Boldin at a great value.
"He's a great player," Kaepernick said. "I don't think you're going to find anybody in the sixth round to come in and play better than what he's doing right now."
Boldin had six catches for 104 yards and a touchdown in the Ravens' 34-31 Super Bowl victory over the 49ers. Boldin also had five receptions for 60 yards and two scores against New England in the AFC title game.
But he was due $6 million in 2013, the final year of his contract. After Boldin and the Ravens failed to agree on a restructured deal, Baltimore worked a deal with San Francisco rather than simply cutting him from the roster.
News of the deal came shortly before several members of the Ravens, including Flacco, gathered to watch a screening of a DVD documenting Baltimore's magical 2012 season.
Boldin and guard Bobbie Williams, whose contract was terminated last week, were featured prominently in the movie. Free agents Paul Kruger, Ed Reed and Dannell Ellerbe may also be gone by the time Baltimore begins training camp in July.
A 10-year veteran, Boldin led Baltimore with 65 catches for 921 yards and four touchdowns in 2012. He was sensational in the postseason, totaling 16 receptions for 276 yards and three scores.
Boldin spent the first seven seasons of his NFL career with Arizona, which lost the 2009 Super Bowl to Pittsburgh. In that game, Boldin caught eight passes for 84 yards.
He came to Baltimore in a trade before the 2010 season. The team reached the playoffs during all three of his seasons with the Ravens.
The Ravens knew changes were coming, so the deal didn't come as a total shock.
"Not necessarily surprised," Flacco said. "You see things like this happen every year in the NFL. It's just the nature of the business. ... Now we've got to put some faith in our young guys and hope they step up to the table and play the way they're capable of playing."
Information from The Associated Press was used in this report.