That'd be my question as well. Being able to gift Infantry and 2000 gold to the most advanced AI is just impressive, to say the least.
Technically, I wasn't
a gift, I got Medicine, but consider this:
Assembly Line is the tech I
loathe to give to the AI. It's #1 on my No Trade list. AL is a vastly powerful tech, it massively increases MFG, it makes Infantry available, it is the Pentagon tech. Yet the AI does not prioritize it much!
So it really felt like shooting my own leg, giving AL to the Wash whom I planned to invade; Wash also being friendly/trading techs to MM, who happened to be the other AI I wanted to invade. Add cash I normally use for deficit research getting techs first for leverage; add I haven't finished Pentagon yet and there's no telling when the AI pops a GE; add I had no need/plans about Medicine whatsoever; and you'll know why it felt worse than gifting.
In particular, I'd like to know
1. how many cities before the war
2. when and why did you decide against a renaissance war?
3. research path from Lib to tanks
4. what did you trade for, bulb, and what did you steal
5. I guess Oxford in capital? when?
6. how to hold Mansa's tech rate and culture at bay?!
1. Seventeen plus the oil settlement.
2. When I knew the AIs can't beat me to settling the lands west...it happened over time, bits and pieces of info like the fact it's the same landmass (which I knew from my first city there), the worldspanning pangea confirmation (Mansa circumnavigated ~1000bc), and partial exploration. Why: with 17 cities I didn't need renaissance war to create an economy stronger than the AI ones.
3. Self-research after Lib->Nationalism went something like: Gunpowder (trades for machinery/optics), Printing, SciMeth via traded for Astronomy, Communism, Replaceable Parts, Steam (trading for stuff like chemistry/steel econ/corps and rifling/mil sci on the way), AL, Facism (had to do that early because of the AL giveaway) , Physics, Electricity, Industrialism, Combustion (after RR trade for Electricity and Facism), Flight.
4. I mention trades. From Washington I stole little: Theology and Mil Trad, but I also spend EP on city revolts to lower defenses. Five spies failing at 55% success rate for one of his cities is why the invasion took me nine turns instead of the planned six however. From Mansa I stole much more in beaker value: Mass Media and Computers, and I also used EP to keep him off Free Speech in the end game.
5. About 900 AD.
6. Wars, and bribing/revolting his civics. I had easy time keeping him off Free Speech in the late game and from time to time I was able to create a lot of unhappy faces too.