If you time travel and take out the ENIAC, you likely deprive the US of working nuclear weapons during WW2.

https://en.wikipedia.org/wiki/ENIAC

ENIAC was designed by John Mauchly and J. Presper Eckert to calculate artillery firing tables for the United States Army's Ballistic Research Laboratory (which later became a part of the Army Research Laboratory).[7][8] However, its first program was a study of the feasibility of the thermonuclear weapon.[9][10]

... choose wisely.

Can you predict what would have happened, then?

...are you sure?