Tuesday morning the nation's highways didn't suddenly become more crowded with cars and trucks, but the U.S. did reach a population milestone of 300 million people.

It happened this morning at 6:46 a.m. CDT. Actually, The Associated Pressquotes a top U.S. Census Bureau official as saying the 300-millionith person probably wasn't added at exactly 6:46 a.m., but he said they're confident that they're "pretty close."

The population hit 200 million 39 years ago, back in 1967. The Census Bureau predicts the nation will hit 400 million in 2043, just 37 years from now.