The 20th Century, saw a vast increase in the population of the United
States—from 76 million inhabitants in 1900 to 281 million in 2000. When the
century dawned, we were an agrarian nation with 72 percent of our population
living on farms and rural areas. It is the automobile that did the most to
change the face of the nation: in infrastructure, economics, and culturally. The
century saw a movement of population, not just into cities, but to enumerable
suburbs that surrounded them. Iowa has not escaped this trend.
1990s, the people of Iowa grew older and more diverse. By 2000, the median age
for all Iowans was 36.6, slightly higher than the National median of 35.3.
Thirty-eight counties had a median age of at least 40. These were all in rural
parts of the state. It is the growth of the baby-boom generation that has pushed
the average age of the population higher. The state was fourth in terms
population older than 65 (14.9 percent), behind Florida, Pennsylvania, and West
Virginia. However 2000 was the first census in half a century where the percent
of Iowans over 65 was lower than the previous decade, falling from 15.3 to 14.9
percent. This was a result of the relatively low number of births in the 1920's
and 1930's. The number of older Iowans can be expected to rise considerably as
the leading edge of the baby-boom generation reaches age 65 in 2011.