Q: How did the Dallas Cowboys become known as America’s Team? And is that a title that they can still rightfully claim, all things considered?A: The date was Sunday, September 2, 1979. The place was Civic Center Busch Memorial Stadium in downtown St. Louis. The temperature was 76 degrees Fahrenheit, the relative humidity along the west bank of the mighty Mississippi River was a dampish 73 percent, and the wind, barely blowing, was light at 7 miles per hour. The playing surface was Astroturf, and the game’s kickoff was set for 2 p.m. Central Daylight Time. The afternoon matchup between the St. Louis Cardinals and the Dallas Cowboys would be broadcast on CBS.But first, before the action was to begin, there would be a televised…