Large scale late-70s/early-80s game show

I need some help trying to recall the name of a one-off game show that was broadcast in either the late-70s or early-to-mid-80s.

This was a fairly standard quiz show which eliminated contestants from one round to the next. The twist was that it started with thousands of contestants assembled in a stadium (I think in Los Angeles, which would point to the Coliseum). They would select their answer (2-part multiple choice) by moving to one half of the field or another.

After the field was whittled down a fair bit, the remaining rounds took place in other parts of the world (I remember London being one such site; maybe Hong Kong was another?). There was a lot of camera time devoted to showing the location itself, along with the plight of the eliminated contestants.

The only question I remember is from the stadium rounds: "Neil Armstrong first stepped onto the moon with his left or right foot?"

I don't think I'm just imagining this... does anyone else remember such a show?

Edit: found it! It's The All-American Ultra Quiz, which aired in 1981:

This two-week game show special (aired 11/10/81) was emceed by TV comedians Dan Rowan and Dick Martin. The program started with 932 contestants at the Dodger Stadium in Los Angeles. After a series of elimination competitions, the remaining 84 contestants were then shipped off to various cities around the globe (Washington, D.C., London, Rome, Paris and Athens) for additional competitions. The winners moved on to the next challenge and the losers paid their way home. When the two finalist returned to the NBC studios, they competed for a $100,000 grand prize. Craig Power was the winner.

And it wasn't thousands of contestants. Then again, everything seemed a lot bigger back then (my parents' old house, my grandparents' house in Chicago, etc.) -- I've been astonished to see just how small they really are when revisiting them.