September 26, 2012

Boom and Bust: What Happened to Montana's Population in the Early 20th Century

By Jeff Malcomson
Government Records Archivist

At the 39th Annual Montana History Conference, held here in Helena last weekend, several members of the MHS staff participated in sessions on the conference topic of homesteading.  In my presentation on the Homestead Boom and its impact on politics and government in MT, I included a couple Powerpoint slides detailing the remarkable population explosion Montana experienced from 1900-1920, and how it came to an end in drought and depression.  I want to share two of these slides in order to reveal their meaning for Montana at this crucial time in its development.
This map shows population growth in Montana by regions from 1900-1920.  The eastern counties grew at the highest rate for the period by far, though the central counties added more total residents.  The western counties displayed a large influx of people in the first decade of the new century, largely due to the opening of the Flathead Reservation to settlement following the allottment program.  However, the western and southwestern sections grew much more slowly than the rest of the state during the period.  By 1920 the central and eastern regions of the state held the majority of Montanans for the first time.  This distinction would hold until the census of 2000 when newcomers to areas like Missoula, Kalispell, and Bozeman would finally surpass eastern and central Montana.

Montana's population grew rapidly each year throughout the 1910s as homesteaders and others flooded into eastern and central Montana.  The chart above displays estimates for Montana's population during this period of the most rapid growth in the state's history.  The state government provided estimates of the state population each year starting in 1915 in its main promotional literature.  They appear to be rough estimates of unknown origin; the state had no real way to gauge population growth at that time.  The figures in the black boxes represent U.S. Census numbers for 1910 and 1920.  I developed my estimates by compiling state school census figures for the period as found in the annual reports of the Superintendent of Public Instruction, which documented the population of people 21 years of age and under.  I applied the rates of growth of this population of Montanans and simply applied it to the entire population.  Despite some drawbacks and possible overstatement in my methods, I believe it to be the best estimate we can obtain for the period.  It is important to note when looking at the chart above that a serious drought began impacting Montana in 1917 and continued until 1921.  The school census figures and other problems lead me to conclude that there may be undercounting issues with the 1920 U.S. Census in Montana.


  1. Interesting... how reliable do you think the counts in the City Directories are? (I realize that would not total to the state. Just curious.)

  2. City directories serve a purpose, which I believe is primarily tracing people between censuses (even occasionally providing death info), tracing businesses, and providing interesting historical tidbits about communities that very few other sources can. I think we need to experiment more with directories, especially for the 1910s, to see what the actual limits of their use are. The population figures given in the introductions of each community in directories are suspect in my opinion. They appear to have more accuracy for larger communities, like Lewistown, which were well covered by directories. For smaller communities and rural farming and ranching areas, especially those growing so quickly during the homestead boom, I believe the directories population figures are much less helpful. The names are there and can be counted; I must admit I haven't attempted this yet. So I think there's some potential for using directories to assist in establishing historical population figures, but they are only part of the puzzle. Thanks for your interest!