Assassinating Lincoln at the end of the war rather than assassinating him before it began.
Not realising slavery is barbaric and freeing the slaves.
it was a bold strategy that didn't pay off.
shareThey should have allied with Spain...
https://en.wikipedia.org/wiki/Carlos_Manuel_de_C%C3%A9spedes
Carlos Manuel De Céspedes was a landowner and lawyer in eastern Cuba... On 10 October 1868, he made the Grito de Yara (Cry of Yara), declaring Cuban independence, which began the Ten Years' War. That morning, after sounding the slave bell, Céspedes announced that they were all free men and were invited to join him and his fellow conspirators in war against the Spanish government of Cuba.
https://www.imdb.com/title/tt6335696/?ref_=nv_sr_srsg_0
"The Cuba Libre Story" (2016) really interesting history.