He only made one appearance on the MCU, so what happened to Tommy Lee Jones' Colonel Chester Phillips after Captain America: The First Avenger? Captain America had actually received three movie adaptations prior to his MCU introduction. Reb Brown played the titular hero in a duology of TV movies in 1979 that was expected to lead to a series. These two movies were cheaply made and failed to capture the appeal of the character, with sequel Death Too Soon only being notable for the casting of Christopher Lee as the villain.
Michael Winner was attached to direct the 1990 Captain America movie before Albert Pyun took over. Matt Salinger played Steve Rogers but it again suffered from a low budget and wound up going straight to VHS in the U.S. Chris Evans was initially reluctant to sign on for Captain America: The First Avenger due to fear of being typecast and locked into a multi-film contract, but he later admitted this was one of the best decisions of his career. Evans has come to define the superhero onscreen and he ended up playing the part in ten films, though some of those were cameo appearances like Spider-Man: Homecoming.
Captain America: The First Avenger is unique amongst MCU outings for being a period film, detailing Steve Rogers' origin story. One key character who appeared in the film was Colonel Chester Phillips, played by Tommy Lee Jones. Phillips is very much a character in Jones' wheelhouse, being a grumpy and gruff commanding officer who still comes out with some killer quips now and again. He heads up the project to create an army of super-soldiers, which ends abruptly after scientist Erskine is assassinated following the creation of Captain America.
Like Hugo Weaving's Red Skull, Tommy Lee Jones' appearance in the MCU was a one and done affair and the character never reappeared. This makes sense narratively, of course, considering the film ends with a 70-year time jump. There's not a ton of information on what happened to him after the events of Captain America: The First Avenger, though it's known that he, Howard Stark and Peggy Carter went on to co-found S.H.I.E.L.D. together in the 1950s, with his photo later seen in Camp Lehigh in Captain America: The Winter Soldier.
Colonel Phillips eventually passed away in 1970, though the character was rarely brought up in later MCU entries. Still, he left a lasting impression on both Rogers following the events of Captain America: The First Avenger and the MCU by helping found S.H.I.E.L.D., although he doubtless wouldn't have been happy with HYDRA's infiltration of the organization in later years.