The news of Boseman's death sent shockwaves through Hollywood and around the world.
"The true power of @chadwickboseman was bigger than anything we saw on screen," wrote Democratic presidential candidate Joe Biden.
"From the Black Panther to Jackie Robinson, he inspired generations and showed them they can be anything they want — even super heroes."
Biden's running mate Kamala Harris said she was "heartbroken" and referenced Howard University in Washington, nicknamed Bison, where they both studied.
"My friend and fellow Bison Chadwick Boseman was brilliant, kind, learned, and humble," she tweeted. "He left too early but his life made a difference. Sending my sincere condolences to his family."
Boseman's final post to Twitter, on August 12, was to congratulate Harris the day after she was announced as the Democratic candidate for vice president in the 2020 election.
Chris Evans, who played Captain America in the Marvel series, tweeted: "Chadwick was special. A true original. He was a deeply committed and constantly curious artist. He had so much amazing work still left to create. I'm endlessly grateful for our friendship."
Another of Boseman's Marvel co-stars, Mark Ruffalo, tweeted: "Brother, you were one of the all time greats and your greatness was only beginning. Lord love ya."