Glad you wrote this, Tim. It's become disturbing of late how many antiracists writers, here on Medium & in mainstream publishing, have taken to attacking Lincoln, many taking points directly from classic Neo-Confederate, Lost Cause playbooks.
E.g. Lincoln sought only to preserve the Union, not free slaves, the E.P. not, initially, freeing slaves in the border states, Lincoln's early focus on colonization of freed men & women, etc...
One prolific Medium writer has argued that were it not for Booth there would be no black people in the United States today (he also claimed Lincoln deserved no credit for the 13th amendment because he died before it was ratified).
One can understand that the legacy of "white saviors" becomes tiresome, especially considering that much of the early heavy lifting in the Underground Railroad, for example, was done by freed men & women. But Lincoln, when all is said, was the real deal. He understood that nothing positive can happen for either slave or free black unless the Union remains whole.
In short, first things first.
Booth was just a damned fool in every respect.