This story is related in Team of Rivals, but Atlas Obscura provides more detail than Doris Kearns Goodwin did! Here’s an episode from Lincoln’s life that is less glorious and noble than some of his other deeds. Turns out, Honest Abe wasn’t great at letting lovers down easy.
In the end, Mary ghosted him. Lincoln concluded his last letter to her stating, “If it suits you best to not answer this, farewell. A long life and a merry one attend you.” She never replied. This left Lincoln smarting. He later claimed, “My vanity was deeply wounded… that she whom I had taught myself to believe no body else would have, had actually rejected me with all my fancied greatness.”
Source: A Breakup Tip From Abraham Lincoln: Just Tell Her Your Town Is Terrible – Atlas Obscura