Hi,
Here are the clues;
1- This is a champion.
2- Another family adopted him/her.
3- He/she made great commercial investments.
4- He/she became a national symbol with his/her accomplishments.
5- There's a movie about him/her
6- He/she didn't start to his/her career with his/her own name.
It is an a real person. We don't know if still alive or not.
The answer is not :
Lance Armstrong
Milkha Singh
Babe Ruth
Demetrius Jackson
Who could this personality be?