Captain America

Steven "Steve" Rogers was born in New York and was growing up during the Great Depression and his dad died when he was young and his mom died after he graduated high school. After hearing about what horrible things that the Nazi's did he decided to join the army. Since he wasn't strong or fast enough to be in the army, when he was offered to be the first test subject on the "Super Soldier Serum" he accepted. While being injected with this serum he was hit with "Vita-Rays" which changed him from being a frail human to a super human. And then, Captain America was introduced.

The Winter Soldier

James Buchanan "Bucky" Barnes was born in New York and was a soldier of the 107th Infantry Regiment and childhood best friends with Steve Rogers. Bucky was assumed dead but came back as The Winter Soldier and was working for HYDRA because they brainwashed him and took away all of his memories and his only job was to do what they told him to do. He can get his memories back but can be consumed again by The Winter Soldier side of him with 10 simple phrases which are "Longing, Rusted, Seventeen, Daybreak, Furnace, Nine, Benign, Homecoming, One, and Freight Car." Which may just seem like random words but they mean more than you think.