Superboy once ventured into the past and tried to make some changes to history, but found that compensating effects seemed to be at play and history was put back on track.
Have Superman or Supergirl ever tried to change history?
Certainly Supergirl tried to change history in the Action Comics #289 story "Superman's Super Courtship" by trying to get Superman to marry Helen of Troy. In the same story she contemplates that Cleopatra would be a good match for Superman but decides against interfering.
In Action Comics #274, "Supergirl's Three Time Trips" she appears to become part of history. For example the flag made by Betsy Ross is destroyed before George Washington can receive it and she creates a new flag.
In Superhoy 85 (1960), Superboy decided to go back to 1865 and save Abraham Lincoln, "changing history for the better."
Superboy tracked down a mysterious Mr. L who he figured must be Lincoln (just go with it). Mr. L turned out to be time-traveling Lex Luthor who just chanced to go back to that time and place. Luthor froze Superboy with Kryptonite and monologued so long that the assassination went on as usual.
To his credit, when he realized that Superboy came back to save Lincoln, Luthor burst into tears, proclaiming he was evil but not that evil.
Superboy may not have changed history but he had every intention of doing so.