I often think that the United States is getting more "crowded". I decided to look up the population of the United States over the years according the Census, starting in 1962, the year I was born.

1962 --> 186,538,000
1970 --> 203,392,031
1975 --> 215,465,255
1980 --> 226,545,805
1985 --> 237,923,795
1990 --> 248,709,873
1995 --> 263,064,000
2000 --> 281.421,906

The official estimate for 2010 has not been released but people are thinking it'll be around 309,000,000. So, over my lifetime, the population has increased from 186.5 million to 309 million, an increase of 122.5 million or around 66%.