Teams played six or seven exhibition games. In 1966 (and 1960), the NFL had an odd number of franchises, so one team was idle each week. In 1978, the league changed the schedule to include sixteen regular season games and four exhibition games. From 1978 through 1989, the sixteen games were played over sixteen weeks.
At 5:36 p.m. on March 27, 1964, a 9.2-magnitude earthquake erupted 78 miles east of Anchorage, Alaska. The earthquake remains the most powerful earthquake to strike North America, and the second-largest earthquake ever measured.
The United States Geological Survey maintains a nearly real-time quake map on their website (in the related links section) if you're interested in seeing where there have been earthquakes in the past week or so. Alaska has the most earthquakes per year, around 12,000. California has the second most earthquakes per year, around 10,000. Hawaii has the third most earthquakes per year, around 8,000.