“Forgettable”? He was one of the most brilliant men ever elected to the presidency. He was a college president and a general in the Union Army in the civil war. He could write with both hands simultaneously, one writing in Latin and the other in Greek. The fact that he was assassinated just a few months into his first term may be why many people don’t know that much about him but he was anything but forgettable.
You’re right; I’ve read that the mourning rivaled that for Lincoln.
Great Johnny Cash song: “Mister Garfield”