Demographic Profile

In 1830 the population of Indianapolis was 1,900 and grew at a long-term rate equal to 5.8 percent per year to reach a population of 314,194 in 1920. During this period, most of Indianapolis’ and Marion County’s population was concentrated in Center Township. For example, in 1920 Center Township, with a population of 283,414, contained 90 percent of the Indianapolis population and 81 percent of the Marion County population of 348,061. Although measures of natural increase (the annual rate of population growth due to the excess of births over deaths) are not available until 1920, these figures suggest that natural increase did not contribute much to population growth between 1830 and 1920. The crude birth rate in Marion County in 1920 was approximately 18 births per 1,000 population, and the crude death rate was 14.7 deaths per 1,000 population, indicating a rate of natural increase of approximately 0.3 percent per year. Thus, most of the population growth between 1830 and 1920 was caused by high rates of in-migration. In Marion County, the number of in-migrants exceeded out-migrants by 57,583 between 1900 and 1910, and by 70,910 between 1910 and 1920.

Between 1920 and 1950, Marion County grew from a population of 348,061 to 551,777 (a rate of increase equal to 1.5 percent per year), Indianapolis increased from 314,194 to 427,173 (1.0 percent per year), and Center Township increased from 283,414 to 337,211 (0.6 percent per year). Suburbanization resulted in an increased proportion of the Marion County population residing outside of both Center Township and Indianapolis. In 1920, 81 percent of Marion County’s population resided in Center Township and 90 percent in the city, but by 1950, only 61 percent of Marion County’s population resided in Center Township and 77 percent in the city.

The population growth of Marion County and Indianapolis between 1920 and 1950 was fueled by high rates of in-migration, low rates of out-migration, declining death rates, and rising birth rates. In Marion County, the number of in-migrants exceeded out-migrants by 51,200 between 1920 and 1930, by 24,500 between 1930 and 1940, and by 36,400 between 1940 and 1950. Furthermore, declining death rates and rising birth rates in Marion County caused the rate of natural increase to rise from approximately 0.3 percent in 1920 to 1.5 percent in 1950. The crude death rate declined from 14.7 deaths per 1,000 population in 1920 to 10.6 deaths per 1,000 population in 1950. During these decades the crude birth rate increased from approximately 18 births per 1,000 population to 25.1 births per 1,000 population.

Between 1950 and 1990 the population of Marion County increased from 551,777 to 797,159 (a rate of increase equal to 0.9 percent per year), the population of Indianapolis increased from 476,258 to 741,952 (1.1 percent per year), and the population of Center Township declined from 333,351 to 182,140 (a rate of decline equal to 1.5 percent per year). Also during this period, the Indianapolis metropolitan area expanded to include Boone, Hamilton, Hancock, Hendricks, Johnson, Madison, Marion, Morgan, and Shelby counties. This metropolitan area had a total population of 831,033 in 1950, with 66 percent of the population concentrated in Marion County. By 1990 the Indianapolis metropolitan area had a population of 1,380,491, with only 58 percent of this population residing in Marion County. Thus, between 1950 and 1990 the eight suburban counties had a rate of growth equal to 1.9 percent per year while the rate of growth of Marion County was equal to 0.9 percent per year.

Despite the slow rate of growth in Marion County between 1950 and 1990, the population of the Indianapolis Metropolitan Statistical Area continued to increase because of high rates of in-migration to the suburban counties and high, but declining, rates of natural increase. Leveling death rates and declining birth rates in the metropolitan area caused the rate of natural increase to drop from 1.4 percent per year in 1950 to 0.8 percent per year in 1989. The crude death rate declined only slightly, from 10.6 deaths per 1,000 population to 8.5 deaths per 1,000 population, while the crude birth rate decreased dramatically, from 24.1 births per 1,000 population to 16.4 births per 1,000 population. Population figures reflect the rapid suburbanization of Marion County. In 1950, 61 percent of the Marion County population resided in Center Township, but by 1990 only 23 percent of the Marion County population resided there. The decline of Marion County population relative to the suburban counties resulted from a relatively higher rate of out-migration than in-migration in Marion County and a higher rate of in-migration than out-migration in the suburban counties. Between 1950 and 1960 in-migrants still exceeded out-migrants by 36,652 in Marion County, but out-migrants exceeded in-migrants by 2,009 between 1960 and 1970, by 89,535 between 1970 and 1980, and by 22,000 between 1980 and 1990. In contrast, among the suburban counties in-migrants exceeded out-migrants by 43,644 between 1950 and 1960, by 35,123 between 1960 and 1970, by 45,697 between 1970 and 1980, and by 9,900 between 1980 and 1990.

*Note: This entry is from the original print edition of the Encyclopedia of Indianapolis (1994). We are currently seeking an individual with knowledge of this topic to update this entry.