That's a pretty dumb semantic argument though, if you're using that argument then you can also no longer claim that white people "ended" slavery.

Yes technically slavery existed much longer, but the argument remains that it's pretty stupid to give yourself credit for ending something that you yourself actively enforced.
And while slavery existed pretty much forever, white people certainly stepped it up a notch after discovering America, it wasn't that common in Europe before that.

As for women voting, America founded its own democracy, so they totally could've given women the right to vote right away if they wanted to, this absolutely is something that they themselves created and therefore they can't really take credit and brag about solving it.