It's the American version of the Caesar cults of the Romans.
The Romans would deify a Caesar and build a Temple to him at Rome. Lincoln's Temple is in the District of Coumbia. His adherents mull over the sacred writings at Claremont University, and keep a sharp eye out for infidels.
There are a lot worse people's papers to mull over than Abraham Lincoln's. He was, by a wide margin, our most eloquent president. There has not been, and never will be, a speech by any president that can touch his second inaugural.