Cinderella Man (2005) on Netflix

Fact-based story of depression era boxing champ James J. Braddock. The film opens with Braddock winning a fight in 1928 and becoming a contender for a championship bout. The film then quickly jumps five years into the future. The depression is on and Braddock has had a series of defeats. Fighting injured, including with a broken hand, made him less of a fighter. Braddock, like many others in that era, lost everything in the stock market and scrimping by on the small fights he can get and on dock work. His wife would prefer he quit boxing, but knows how badly they need the money to get by with their three kids. Watering down milk just to make it do for several more days is a common occurrence. When his trainer manages to get him one more fight on the spur of the moment against the current #2 contender, Braddock rises to the occasion and knocks him out. His amazing comeback becomes the source of inspiration of many down-on-their-luck Americans. A series of fights later leads to the championship match against the arrogant champ, Max Baer. Baer, who had already killed two men in the ring, urges the older Braddock not to fight him. Of course, Braddock feels he has nothing more to lose and very devastating, intense fight ensues. Contains very brutal boxing violence.