Reconstruction ended when it did largely because it was becoming a political liability. The Civil War had been over for twelve years, and most people wanted to move on. The Republicans' commitment to Reconstruction was costing them votes to the Democrats, especially in Northern towns and cities. Crudely put, there were no votes in Reconstruction, because for the vast majority of white Americans, it didn't affect them directly, and so it became more and more difficult to justify the continuation of a policy that only benefitted a relative few, no matter how important it was.
Besides, most white Americans, North and South, believed that African Americans were racially inferior, and so it was all too easy to ignore the outstanding issues that still needed to be resolved in relation to achieving substantive, rather than simply formal, legal equality.