Until recently covenant churches, and the related covenant marriages, was a fringe thing. But it seems to be both spreading and people are getting more serious about enforcing the covenant.
I really have no idea of the history of covenants in the church. And it's hard to see casually because there are a lot of churches that use the word covenant in something other then the litteral contract sense. But from what I have read until the 90's it was something that turned up only in small cult churches lead by a single radical preacher.
Now however it seems to have turned into a movement of sorts. Covenant marriage in particular has gone much further, to the point of being legally recognized in some states.
Jay