After I deleted Revision Control, there was no history button in 3.6

Hi,

I’m not sure what you’re referring to, If you can’t see the Revisions metabox, you can re-enable it through the Screen Options in the upper right of your add post screen when editing a post.

If you’re referring to a option that allows you to control the number of items stored, that was probably part of the plugin, and you’ll need to reinstall it.