Was Rocky Marciano always a heavyweight?

Muhammad Ali must have enjoyed boxing if he did it for so many years. As a young boy, Ali would be inspired by other boxers such as Jack Jhonson and Joe Luis. those boxers made him want to box. Not only did he enjoy boxing as a hobbie but he enjoyed it because it showed all other african-american that they can be somebody if they try and are willing to be brave eenough to take that chance and be made fun of by all the white people who were more famous than him and tougher than him. Ali was not a weak person he showed everyone his strength when he beat Goerge Foreman. After he did this he was then again considerd the Champion of the World again. this shows how much Muhammad Ali really enjoyed boxing.