Kelsey Beechler
BIOB 170 lab
11/11/13
Human Demography in the Gallatin Valley
Introduction:
Demography is a broad statistical study of human populations. Demography is important
in science because it provides statistical data of diversity in populations and reveals
trends within those populations. It is also important in society because it helps to analyze
the relationships between economic, social, cultural, and biological processes influencing
a population. The area of study for this research paper is the Gallatin County in Montana.
Specifically, data will be collected from the cemeteries in Bozeman, Manhattan, Three
Forks, and Gallatin Gateway. We will be studying the survivorship rates in Gallatin
County from 1944-1954 and 1956-1966. It is a common practice within demography to
take headstone data and compare it with statistical data and census numbers to see
connections within the demographics of an area (Sattenspiel et al 2010). The population
within this area during this time was fairly sparse with 16,124 people in 1930, but grew to
26,045 people in 1960 (U.S. Census Bureau 2010). Despite this growth, the population
still lived spread out over the county not creating any major city concentrations.
Polio is a very contagious infectious disease that affected the nervous system and
caused paralysis in mainly children, but could spread to anyone subjected to the disease
through fecal-oral transmission (Singh et al. 2013). Most deaths occurred by suffocation
due to respiratory paralysis. This required the ‘Iron Lung” to be used to keep individuals
breathing. It became a very highlighted disease due to FDR contracting the disease and
helping initiate the March of the Dimes fundraising organization. 1952-1954 contained
multiple successful trials of the vaccine and oral drops by Salk and Sabin (Trevelyan et
al. 2005; Singh et al. 2013). Around 1955, mass immunizations were occurring.
The objective for this project is to study the survivorship rates from 1944-1954
and 1956-1966. Using this, we will look for a change from before and after the
vaccination for poliomyelitis was distributed in 1955 in response to the poliomyelitis
outbreak. Our research questions ask was there a decrease in survivorship in the 19441954 time period? Also, was there an increase in the survivorship in Gallatin County in
the 1956-1966 time period, and if the increase exists, can it be attributed to the
poliomyelitis vaccination being distributed in 1955? Our hypotheses state that by looking
at data collected throughout the Gallatin County, there will be a low survivorship rate
from 1944-1954 pre-poliomyelitis vaccine in 1955. Also, that by looking at the trends in
the data from the 1944-1954 time period as compared to the 1956-1966 time period, there
will be an increase in survivorship after the poliomyelitis vaccine is distributed in 1955.
The null hypothesis states that the vaccine creates no difference in survivorship across the
two tested time periods. This information and these data collection methods could lead to
further connections with other infectious diseases and survivorship rates within a
population.
Methods:
First we had to determine which areas within the Gallatin County would best represent
the population during the mid 1900s. We chose Bozeman, Manhattan, Three Forks, and
Gallatin Gateway. The specific cemeteries were Sunset Hills Cemetery, Bozeman, MT –
45°40’28”N 111°1’30”W, Salesville (Gallatin Gateway) Cemetery, Gallatin Gateway,
MT – 45°36’47”N 111°11’46”W, Fairview Cemetery, Three Forks, MT - 45°52’17”
111°32’1”W, and Churchill Cemetery, Manhattan, MT – 45°45’4”N 111°17’59”W.
To begin collecting data, we went out to the main cemeteries within each town and
recorded information from the headstones on a chart. The chart included birth, death, age,
and which decade category it fell into, be it 1944-1954 or 1956-1966. The data from all
the cities would then be put on one chart, using Microsoft Excel, for each cohort. We
calculated the survivorship by using the amount of individuals alive to the population of
the city at the time. Life tables are used to record the age at death of our sample
individuals. Then this allowed us to calculate the survivorship rate by dividing the total
number of samples by the number of individuals alive. We then took this data and
compared it over the different time cohorts. Also, we would gather survivorship data on a
national level and see if the results are comparable.
Results:
Our data is displayed on two life charts. Figure 1 is the life chart for the 1944-1954
cohort, while Figure 2 is the life chart for the 1956-1966 cohort. By looking at the
survivorship column on Figure 1, one can see there is a decrease in survivorship as the
ages progress. In Figure 2, one can see a similar pattern. These patterns and their
differences were then displayed on a survivorship curve graph for ease of comparison.
Figure 1: Life chart for 1944-1954 cohort. Pre-vaccination
Figure 2: Life table for 1956-1966 cohort. Post-vaccine
Based on the data collected so far that has been displayed on a survivorship curve, the
survivorship between the two cohorts shows some slight variations in certain age groups.
The survivorship for the 1956-1966 cohort has a slight increase in comparison to the
1944-1954 cohort in the ages of 40-100 years old. There is also a slightly lower
survivorship in the post-vaccination time cohort from ages 10-30 (Figure 3).
Figure 3: Survivorship graph
Discussion:
Our hypotheses were looking for a low survivorship in the 1944-1954 cohort and an
increase in the survivorship for the 1956-1966 cohort. We were looking for an increase in
the survivorship from when poliomyelitis was most prevalent to when after the
poliomyelitis vaccinations were distributed in 1955, in order to see a correlation between
that event and the deaths of that time cohort. Our data does reflect an increase in
survivorship for the post-vaccination cohort amongst a certain age groups. This could
range to as much as a 10% increase.
As we cannot distinguish what each individual that was recorded died from, we
cannot definitively say that the poliomyelitis vaccine is the cause for the increase in
survivorship. Our results did answer our objective, to find the survivorship rates and find
a difference between the two cohorts of before and after the poliomyelitis vaccination in
1955. Some interesting points found within the data is that, while the disease affected
children most, people aged 40 and below had a fairly high survivorship, while the old had
the sharp decline. This could be due to the weaker immune systems of the elderly, but
there is no explanation for the higher survivorship amongst the young.
Compared to other demography research, we followed similar procedure and
produced results based off of that. Our topic wasn’t replicated in any research we found,
so our results are fairly unique. We also dealt with a more local approach, while many
demography research projects were done a bit larger or national scale. By taking data
from cemeteries, our data is automatically limited. People could have been buried
elsewhere, we could have not collected the entire possible data for each area, and for
some, they may not have been buried within a cemetery, but rather in a private plot.
If there was to be future research done on the area with this topic, with more
access, we could have gotten national records or health records for the area to see if
poliomyelitis was documented in any way. Also, we could have accessed more of the
areas within the county, thus giving us more thorough data. It is almost impossible to
attribute all of these trends and records to a specific cause. During this era, there were flu
epidemics, diseases and death from the war, and deaths due to the elderly generation
dying of natural causes. Based off of our data, we have at least found something to
contribute a correlation between the rise in survivorship and the vaccination distribution.
With further research, more solid information could be found
Literature Cited:

Sattenspiel, Lisa, and Melissa Stoops. "Gleaning Signals About the Past From
Cemetery Data." AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 142:7–21
(2010) 142 (2010): 7-21. Print.

Singh, Robin, Amit K. Monga, and Souravh Bais. "POLIO: A REVIEW." International
Journal of Pharmeceutical Sciences and Research 4.5 (2013): 1714-724. Print.

Trevelyan, Barry, Matthew Smallman-Raynor, and Andrew D. Cliff. "The Spatial
Dynamics of Poliomyelitis in the United States: From Epidemic Emergence to
Vaccine-Induced Retreat, 1910–1971."Annals of the Association of American
Geographers 95.2 (2005): 269-93. Print.

" ." US Census Bureau. N.p., n.d. Web. 16 Oct. 2013. <http://www.census.gov/>.