Monday Night Football

Monday Night Football began as an idea that the NFL tried to sell to CBS or NBC. Both networks declined. CBS had the successful "Laugh In" on that night, and NBC had the "Doris Day Show." ABC was the last to be offered the deal, and they jumped on it. In September of 1970, Monday Night Football made it’s debut. It, of course, was wildly successful, and is still on today.
Incidentally, one of the main arguments against prime time, weekday football was that women would never watch, which might keep households from watching. In 2003, women made up a little over 40% of the Monday Night Football audience.