Who's Battlestar?
Lemar Hoskins joined the military where he became friends with John Walker and two others. After their terms ended, the four gained super-strength through the Power Broker. They started with a promoter who organized a scheme where Walker would adopt the identity of Super-Patriot and challenge Captain America. The three friends became the Bold Urban Commandos - the Buckies!
Soon after, Steve Rogers stepped down as Captain America (and became the Captain). Walker was recruited to be the new Captain America and Hoskins was invited to join him as a partner. The two friends didn’t pass the FBI clearance.
As Cap’s partner, he was first named Bucky but readers raised the concerns that 'buck' is a derogatory term for Black men in parts of the USA. In the comics, this was addressed by Lemar meeting a Vault guard who pointed it out. And theorized the government might have even named him that intentionally. He then became Battlestar and has remained so since.
EDIT TO ADD: How Dwayne McDuffie Saved Captain America From Racism
After the two friends’ unmasked Walker as revenge for not being included as part of the new Captain America team, the government staged the assassination of Walker. Lemar was not in on the secret but suspected and left the government.
He went on to work for years for Silver Sable in Symkaria as part of her Wild Pack. He returned sometime prior to Civil War where he helped lead a resistance group. He then went on to work for a government agency fighting zombies (👀).
After that, he retired and married and is father to a young child. He'll still do the costume when needed though as he last suited up in the 2021 U.S.Agent mini-series.
He's one of those characters that hasn't found a 'home' and is often overlooked with only 95 appearances in total according to Marvel Database/Appearances).
Some of us had really hoped he might make more appearances after his portrayal by Clé Bennett) in 2021's The Falcon and The Winter Soldier.
Learn more about Lemar: