Southern whites tried to fight back with violence, like making the KKK. When Grant was elected, he passed the Klan Act to remove this group, helping the African Americans, and helping the 15th amendment. That was the beginning of the end. African Americans lost education opportunities since schools were defunded. Republicans were tired since reconstruction took a while, so they let the Democrats control
Reconstruction if they let them control the white house. The democrats spent the next decades undoing everything from the last decade.
Any good things Reconstruction created were kind of switched back which put us back almost 100 years. In conclusion, reconstruction was a failure, it’s not about the mistake though, It’s about how you fix it. A few of these problems still exist today, such as racism, inequality etc.