The world will finally reach peace no more hunger and poverty everyone will be rich and we will live happily ever after! :D This is optimistic because it is hopeful and confident about the future hope this helps! ^0^
To be honest, I dont know. I'm actually not an American. :)
But If i had to pick one major event...it would be making George Washington the president.
To explane.
George Washington's presidentsy in a way made America, in some aspects, what it is today.
Now imagine if he was not made a president but chose to be a dictator. I know its funny and my nest statement is going to be even funnier.
Assassins Creed 3: The rule of King George did a decadent job in imagining and explaning this. I recommend reading its plot, I think you would find it interesting. Its full of what ifs and alternative history events.
Sorry for not giving my version but its a bit hard for me to imagine something like that.
Northern places like Canada were colonized by France. The mid part was at first colonized by the Dutch but then the colonies were taken by the British. The central American part, including South America and the Carribean was mostly controlled by the Spanish. Portugal had control of Brazil while Russians started slowly moving towards Alaska but couldn't establish colonies until the 18th century.