One of the first such redevelopment and planning efforts in the Bay Area was SPUR, San Francisco Planning and Urban Research Agency, started shortly after the "Telesis" exhibition of the San Francisco World's Fair. It was populated by a horde of newly graduated New Deal architects from Berkeley and such, IOW people trained by the faculty recently implanted (or infested) with Marxist Frankfurt School refugees from Germany. Believe it or not, my dad was just such a planner for the City of Richmond in the late 1950s.
I believe it wasn't until the mid-70s that LAFCO started allowing formation of redevelopment agencies with powers of eminent domain pursuant to a change in State law, but I haven't found it yet. Sounds like a Gerry Brown deal, doesn't it?