In a fun essay named The Eighteenth Brumaire of Louis Napoleon, though apparently lifted by Marx from a letter to him by Engels:

https://en.m.wikipedia.org/wiki/The_Eighteenth_Brumaire_of_L...

So really it was Engels.

"First time is not first, second time is an inaccurate citation." Could we settle on this?

Isn't that more or less Stigler's Law of Eponymy?

[0] https://en.wikipedia.org/wiki/Stigler%27s_law_of_eponymy

That was someone else.

Maybe the first time. ;)