Who Could Replace Captain America in the Marvel Cinematic Universe?

Isaiah Bradley

Shortly after Captain America successfully used the only dose of Super Soldier serum, a German spy killed Dr. Erskine, the creator of the serum, leaving America without any way to produce more super soldiers. Desperate to create another Captain America, the US government turned to experimenting on African-American soldiers. The US Army took 300 black soldier to a secret base and gave them doses of Super Soldier serum, in a clear reference to the US Army's real experiments on black soldiers at Tuskegee. Isaiah Bradley was the project's eventual sole success, a black soldier with all the abilities of Captain America. Bradley went on a suicide mission to destroy the German version of the Super Soldier project. Although his mission was successful, the Germans captured and held Bradley until the war's end.

The postwar years weren't kind to Bradley. The Army court-martialed him and sentenced him to prison and his mental state deteriorated due to the imperfect Super Soldier serum he used. While history largely forgot about Bradley, Steve Rogers learned what happened to Bradley and became friends with him. Bradley's grandson would also become a superhero, Patriot, joining the Young Avengers and gaining his grandfather's abilities after a blood transfusion.

William Naslund

After Steve Rogers disappeared during World War II fighting Baron Zemo, the United States passed the mantle of Captain America to William Naslund to keep the spirit of the hero (and the accompanying morale) alive. Naslund was originally a patriotic hero named The Spirit of '76, who fought German spies while dressed in a tricorn hat and a fireproof cape. As Captain America, Naslund joined the Invaders, and helped stop several Nazi plots at the end of the war. Naslund's time as Captain America was sadly brief; a robot trampled him while trying to kill a young John F. Kennedy.

Jeffrey Mace

Originally a Golden Age superhero named the Patriot, Jeffrey Mace was one of Marvel's less popular patriotic superheroes. A reporter for the Daily Bugle by day, Mace protected America from Nazi spies and other "home grown" threats during World War II. After watching William Naslund get trampled to death by a robot, Mace put on a spare Captain America costume and helped stop the robot from killing John F. Kennedy. The US government recruited Mace as Naslund's replacement and served as Captain America for four years until retiring in 1950. Mace was one of the few Captain Americas to not suffer a major tragedy during his career. He happily married the Golden Age superheroine Golden Girl and lived well into his 80s, dying peacefully with Steve Rogers at his bedside.

William Burnside

The "evil" Captain America, William Burnside was a Captain America fanatic who underwent radical plastic surgery to look and sound just like Steve Rogers. After discovering an imperfect version of the Super Soldier serum in a Nazi scientist's journal, Burnside used the formula to become an unsanctioned version of Captain America in the 1950s. While Burnside enjoyed some initial success fighting communists and a new Red Skull, he went insane, forcing the US government to capture him and put him into stasis. Burnside returned in the 1970s as a pawn for the Marvel villain Doctor Faustus. Becoming the Grand Dictator, a brainwashed Burnside led a neo-Nazi group called the National Force until he was defeated by the returned Steve Rogers and Daredevil. Burnside resurfaced after Rogers' alleged death still under Doctor Faustus's control. After trying to assassinate two US presidential candidates, Burnside joined a right wing militant group trying to bomb Hoover Dam. Bucky would shoot and grievously wound Burnside, leading to his eventual recapture.

Roscoe Simons

After Steve Rogers abandoned the shield during the 1970s, Roscoe Simons, a fan of Captain America, became his replacement, beating out two other candidates, Bob Russo and Scar Turpin. Working with the Falcon, Simons used Captain America's shield but had no other superpowers. Simons was only Captain America for a few months; the Red Skull crucified and murdered the replacement Captain after discovering Rogers had quit. Simons' death pushed Rogers into reclaiming the Captain America identity despite Rogers' ongoing problems with the US government.

John Walker

Conceived as a more extreme version of Captain America, Marvel introduced ex-soldier John Walker as the pragmatic Super-Patriot in the 1980s. Walker was less idealistic than Steve Rogers and believed he represented America's ideals more than the out of touch and outdated Captain America. Much to his chagrin, the US government recruited Walker as Rogers' replacement when the latter abandoned the Captain America identity during one of his many fights with the government. Walker was a brutally violent Captain America, beating, killing and maiming many of his enemies. Rogers and Walker would later reconcile and Walker would become the superhero US Agent after Rogers retook the Captain America mantle. Tragedy has marred Walker's superhero career: supervillains murdered his parents, the US government has repeatedly used and manipulated him, and he even lost an arm and a leg during an attack by the supervillain Nuke. Still, Walker remains a patriot to his country, choosing to serve however he can.

Bucky Barnes

In 2005, writer Ed Brubaker shocked the world when he revealed the mysterious Russian assassin the Winter Soldier to be Bucky Barnes, Captain America's long presumed dead sidekick. The Winter Soldier was only the start of Barnes' modern day story; he would later take Steve Rogers' place after Crossbones allegedly assassinated Rogers at the end of the superhero Civil War. Barnes served as Captain America for several years, joining the New Avengers and fighting the Red Skull and other classic Captain America foes. Barnes would continue as Captain America after Rogers returned for a while, until Sin, the daughter of Red Skull, beat him nearly to death during the Fear Itself event.

Sam Wilson

You probably remember the headlines from last year declaring Sam Wilson to be the new Captain America. Wilson was Steve Rogers' longtime partner and friend, who fought alongside him as the Falcon. After the supervillain robot Iron Nail aged Rogers back to his "real" age, he turned over the Captain America mantle to Wilson, giving him his indestructible shield and a new flying costume. Wilson's only been Captain America for a short period of time, but he'll continue to serve as Marvel's new Captain America as the company launches its All New, All Different Marvel line.