Redditor buys used Martin Luther King Jr. book online, discovers autograph inside

A book lover looking to save a few bucks may have ended up with a priceless piece of history.

Reddit user captain_fishy recently ordered a used copy of Martin Luther King Jr.'s 1963 book "Strength to Love" from Amazon for just $3.50.

When it arrived, he discovered a personal message scrawled to its original owners on the first page. It appeared to be signed by Martin Luthor King Jr. himself.

Captain_fishy posted images of the book and its autograph on Reddit, hoping that someone would be able to verify the signature's authenticity.

"If anyone can help me determine if it's real I would be much appreciative. I've looked up MLK's signature and it seems to match up pretty well. Thanks!" he wrote.

Some Redditors linked to digital copies of MLK's signature while others cautioned that getting the signature authenticated could cost more than the book is really worth. The book's owner responded that he'll consult with a university professor first, "but of course I may never know."

Captain_fishy fully intends on keeping the book, authentic signature or not.

"Definitely not thinking of selling it. It's one of the luckier things that's ever happened to me if it is real," he wrote.

"I think I may just put it on my shelf and believe it's real for the rest of my life…" he added.

"I will definitely take care of it. He was an amazing man from the small amount I know."

Redditor hnice wrote that the book itself is worth getting excited about:

"Since everyone's going to be fixated on the signature, just wanted to pipe up and say what an amazing book this is, signed or unsigned. The 'Peter, put up thy sword' sermon alone — I'm not a religious person, but there's so much great writing in 'Strength to Love.'"