I never thought about it I grew up in the 60s so Free love and all that. I never questioned it but I did do a quick search and found this. I don't know how accurate it is
The word Free in the Evangelical Free Church's name refers to its congregational polity, meaning each member church is autonomous, and to its history, meaning that the free churches were free from state control. The governing body of the EFCA is the Leadership Conference held annually.
It sounds about right because the one that I was attending that left that was part of the problem was the mother church was trying to control them and their their philosophy was that they were not receiving any money from them like to pay the rent or anything so they shouldn't be able to control how they run things. That was the disagreement and reason for the breakup. They weren't allowing them to be free.