Good day, Madam
My name isn't Adam
I was the man
Who had two plans
The first one succeeded
The second, also needed
Did not work, and at that
A tip of my hat
To the Yanks, who completed
The work that defeated
This good man, never odd or even
Though able was I, I was not quite forgiven
Who am I?
Edit: Here is a first hint to get you started:
I am a historical figure, but you probably never heard of me.
Edit: And here's another hint (added after the riddle was solved):
But you definitely heard of some of the achievements I'm famous for, alluded to in the riddle.