Steve Rogers is by-and-large the most well known Captain America. Being the star of the Marvel Universe, for many fans Steve Rogers is THE Captain America. However, that hasn't always been the case, in fact, there have been numerous people over the decades who have picked up the shield and become Captain America. Many fans will know of the first two people on this list, as they are being hotly contested for the role of Captain America after Chris Evans leaves the universe (if that every happens). Gathered below are the 5 most notable characters that have been Captain America!
Sam Wilson AKA the Falcon is the current Captain America in the Marvel comics as of 2015. When it was announced that Sam would take up the shield, it led many fans into believing that Anthony Mackie, who plays the Falcon in the MCU, would become our next Captain America. When will this happen? My bet would be right after Civil War, however, I think the next person on this list has a better chance of becoming the MCU Captain America.
James "Bucky" Barnes
The former Winter Soldier became Captain America in the Eisner Award winning run written by Ed Brubaker. In atonement for his sins as the Soviet controlled assassin Bucky Barnes is convinced by Tony Stark to take up his best friends mantle and continue Steve's work after he is killed following the events of Civil War (hence why I believe Bucky will be our MCU Captain America). Add to the fact that Sebastian Stan, who currently portrays Bucky in the MCU, signed an at least 9 picture deal means that he has a lot more to offer us in the future.
That's right the same Scott Summers that belongs to the X-Men. The same Scott Summers that goes by the alias Cyclops. How exactly did he become Captain America? Well, in the Ultimate Universe (an alternate universe within Marvel Comics) Alternate Future, the Steve Rogers of that reality dies leaving his shield up for grabs. Around the same time, Scott Summers loses his powers but still wishes to lead his X-men. So he revamps the shield and costume to fit with the X-men color scheme, including the official X-men "X".
One of few women to go by the moniker Captain America. Roberta is from the Marvel 2099 universe, which takes place in the year (you guessed it) 2099. Similar to the Civil War Captain America, Roberta fought for the rights of superheroes who were being forced to essentially register and work for a certain organization in order to operate as heroes. However, Roberta's Captain America is unaware of her alter ego, and Roberta is unaware she is Captain America. Her split personality keeps each side of herself unknowing of the actions of the other.
The grandfather to Young Avenger Patriot, Isaiah Bradley first appeared in Truth: Red, White, & Black in 2003. In it we learn that Steve Rogers was not the only person subjected to the Super Soldier program, and under code name Project: Rebirth the government was attempting to recreate the serum used to turn Steve Rogers into Captain America. They subjected 300 African American men to the tests, in an attempt to create a new Captain America. The operation was a joint project by the governments of the United States, Germany, and Britain.
Sometimes our favorite heros aren't always themselves. These are just a few instances in which Captain America wasn't really Captain America. Will we ever see any of these people in the MCU? Possibly. Most likely we'll see either Sam Wilson or Bucky Barnes take up the shield once Steve inevitably leaves us.