Series, James Polk belongs as one of the greatest: he put the manifest in Manifest Destiny. Texas and Oregon entered the union. We took Mexico City, looked around and left it to them.
He put the world on notice that the middle of north America, from the Atlantic to the Pacific and between Canada and Mexico, belonged to the united States.
Of course this also set us up for the war between the states about ten years later.
Feel free to vote for Polk in the “Other” section. I didn’t want to list every president, and I knew going in that there would be some favorites left out. Someone wrote in Andrew Johnson, I’m assuming because he fought against the Radical Republicans’ play to strengthen the federal government. I don’t agree with him being the greatest, but I allowed a write-in for those who supported presidents not on the list.