There have been quite a few movies where people go back in time to change the past so that the present is altered. On top of my head are Back to the future (2), Men in Black (2), one of the recent X-Men movies where Logan goes back, one netflix movie I'm unable to get the name of and if I think hard, I'm sure to come up with at least half a dozen movies or more which showed that to great effect.
While Stephen Hawking has dissed the idea of making a time-machine which can go to the past from the time a time-machine is invented (pity) does anybody know the first movie which used the trope.