[4] 1720AD - Louis cancels the copper + money for iron deal with us, because apparently we have declared war on his friend.

Well, if you don't want iron... Saladin offers Divine Right and 180 gold for Nationalism... Umm, why would we want DR again? No.
Some logistics moving troops around.
I also realize this turn that something untoward is going. All the workers are sleeping, whereas they should be busy building rails!

This oversight is promptly fixed.
We also kill off HC's crossbow/elephant/mace stack that exited MP, apparently wanting to retake O-town. We take no losses.
[5] 1725AD - Louis offers Divine Right and 300 gold for Education. Again, no! We don't need no divine right.
American civilization is now home to 20million people.
Also, Huayna just doesn't give up.

He moved another two maces and a cat towards O-town. Of course, they were easily picked off by our riflemen in the field.
[6] 1730AD - We get Assembly Line! Start on Scientific Method. If we can nab physics first, we would get a great scientist and be one step closer to another Golden Age.
We bombard the defenses of MP down to 24% and attack. We kill three defending longbows and a pike without taking any losses. There's only one pike left in the city, but the only two available attackers are badly wounded and have unfavorable odds against them. So, I decide to wait another turn and attack with more fresh troops instead.
[7] 1735AD - Machu Picchu falls.
All the soldiers at MP are upgraded to Infantry so as to better dispense ass-kicking on the Inca.
Note HC is trying to sneak off on a ship loaded with a settler and two longbows. Of course, I can't let him get away. Unfortunately, I don't have any Frigates around (this reminds me: we need more frigates), but I do send two galleons to intercept the Incan ship.
I also move research up to 90% so we can get Scientific Method in one turn.
[8] 1740AD - We get SM, start on Physics.
We sink the Incan settler galleon, luckily sustaining no losses. We also kill an Incan elephant and catapult, but, unluckily, lose a cavalry in the process. Go figure. The troops are healing in MP.