You may well do so. Mrs. Grant dictated the memoirs, she didn't write them. They were edited by John Simon, who is credited as author instead of Mrs. Grant. And then, of course, there is the fact that the Grant family must have deliberately violated the laws of the state of Missouri, or Illinois, or the District of Columbia, or Ohio, or wherever they lived when the 13th Amendment was ratified, yet somehow this has escaped all his biographers. But hey, believe what you want.
So she didn't read them when they were done. Didn't check to see what the ghost writer put down on paper. Alright...it's late, so we'll go with your crazy theory because heaven forid Julia Dent Grant knows when her slaves were freed. No...not possible. It's a conspiracy theory.
Who killed Lincoln?
Who killed Kennedy?
Who was responsible for 9/11?
Who changed Julia Dent Grant's memoirs and made NS look bad on a thread?
Inquiring minds want to know...