President Abraham Lincoln was president through the four years of the Civil War(1861-1865). He had promised in his election campaign that if elected, he'd end slavery. What you may not know is that President Lincoln started our national Thanksgiving holiday. He issued a proclamation saying that the last Thursday of each year would be a national Thanksgiving Day holiday. And, you may not know that Abraham Lincoln didn't like the name Abe and that even his wife called him by the name Lincoln.