1930 and 1970 Population
H. Dearborn J. Goicochea Duclos
Statewide Population Growth
As the first large wave of immigration in the 1840s increased the rate of
change in the landscape, political boundaries began to emerge. Oregon was
organized as a territory in 1848, and, with the continuing influx of settlers
during the 1850s, was admitted as the thirty-third state in February 1859. The
population of the Oregon Territory was first separately enumerated in 1850
by the federal census (see Mapping the 1850 Census, pp. 52-53).
The free land provided by the Donation Land Claim Act to anyone
settling and making improvements proved a powerful incentive to pioneers.
The 1850s created a boom in the state’s population, almost entirely within
the Willamette Valley, and this trend continued into the late 1800s. Economic
recession and changes in farming contributed to the first dip in the decadal
rate of population growth from 1890 to 1900.
More recently, during the 1940s, Oregon’s population boomed again,
with both the natural rate of increase and in-migration greater than any
previous decade. In the 1960s, birth rates declined, and the natural rate of
increase was the lowest on record except for the 1930s.30 During the decade
1950-1960, however, in-migration increased to 188,000 persons, with a total
statewide increase in population of 247,346. The 1960-1970 increase rate of
18.2% was surpassed in the decade from 1970-1980, with a 25.8% increase.
However, the total increase in number of people from 1970-1980 was
541,623, which is significantly larger than the number of people added in the
previous decade. An economic recession in the early 1980s caused population declines in the first few years of the decade, and contributed to a decadal
growth rate of 7.9% from 1980-1990, the lowest rate on record.68 Although
the rate of increase was lower, the total number of people added to the state’s
population was 209,165, which is almost as many as from 1950 to 1960, and
is approximately two-thirds as many as the sizeable increase from 1960 to
1970 (Fig. 72). As the total population increases in size, even small percentage rates of increase result in large increases in total numbers of people.
POPULATION INCREASE BY DECADE
294.7
81.8
1900
413,536
95,832
30.2
1910
672,765
259,229
62.7
1920
783,389
110,624
16.4
1930
953,786
170,397
21.8
1940
1,089,684
135,898
14.2
1950
1,521,341
431,657
39.6
1960
1,768,687
247,346
16.2
1970
2,091,533
322,846
18.2
1980
2,633,156
541,623
25.8
1990
2,842,321
209,165
7.9
2,000,000
1,500,000
1,000,000
500,000
1980
142,936
1990
317,704
1960
1890
1970
92.2
1950
73.3
83,845
1930
38,458
174,768
1940
90,923
1880
1920
1870
2,500,000
1910
39,171
1890
52,465
TOTAL POPULATION
1900
1860
3,000,000
1880
13,294
%
Incr.
1870
1850
# Pop.
Incr.
1850
Total
Pop.
1860
Census
Year
Figure 72. Population of Oregon 1850-1990 by decade. The table shows
total state population and the increase in population from 1850-1860 to
1980-1990, as well as the rate of increase in percentage by decade. The
chart shows the total population and increase in population by decade.
In the 1990s, the population growth rate was again on the rise, as the
state and national economies expanded. The lower rate population increase
during 1980-1990 appears to be an anomaly, and current trends forecast a
doubling of population in the WRB in the next 40 to 50 years.
Population Settlement Pattern and Population Density
Prior to 1850, almost 95% of the EuroAmericans in Oregon lived in the
Willamette Valley, without any significant clustering of population. Statewide by 1850, Native populations had been greatly reduced in number by
disease, had been removed to reservations, and were soon further reduced in
number by wars with immigrating settlers. By 1880 the total statewide
population was almost 175,000, roughly approximating the present distribution, with less than one-tenth the present density. Nearly 60% of the state
population was concentrated in the Willamette Valley, with a definite cluster
in Portland. By 1940, Portland accounted for 39% of the total state population, with most of the population concentrated in urban areas. Non-urban
54
populations were beginning to decline as a percentage of the total, and in
some parts of the state in absolute numbers as well. This statewide pattern
continued and in 1970, 40% of the state total lived in the Portland metropolitan area, with another 30% occupying the rest of the Willamette Valley.30
As the state economy continues to change from a resource-based
economy, mainly forestry and farming, to a high-tech manufacturing and
information-based economy, the pattern of increasing concentration in urban
areas, where most jobs are located, and in some rural residential areas, will
continue.
WRB Population Density 1930 and 1970
We measure phenomena such as population density to understand and
analyze population patterns over time, and subsequently utilize the results in
planning and decision-making. Aggregation is the process by which information from the records in a database which describe a particular area are
totaled or averaged. But comparisons of data sets are possible only to the
extent that the data sets share common definitions. In the case of calculating
population densities in the WRB over time, areas of measurement change as
the political boundaries like cities and counties change, and as the U.S.
Bureau of the Census redefines census boundaries from election precincts to
census tracts and blocks. For example, in 1930 there were 443 divisions,
called Minor Civil Divisions (MCD), within or intersecting the area of the
WRB. But by 1970 the number of divisions was reduced to only 281, with a
name-change to Census County Divisions (CCD) (Fig. 73). In contrast, the
1990 calculation for population density was based on census block information, and there were 46,077 census blocks which intersected or fell within the
WRB (see pp. 56-57). The areas within the 1990 census block boundaries are
much smaller than the MCDs and CCDs for 1930 and 1970 (Fig. 73).
In 1930, the population count was based on election precincts and
secondary divisions incorporated as cities and towns. These Minor Civil
Divisions were subdivisions of counties, but tended to be rectilinear and did
not follow any physiographic features like rivers or ridges. The tabular data
were separated by precincts, with the population numbers listed for secondary divisions within cities and totaled for the city precinct,69 but the 1930
Census map shows no boundaries for the smaller secondary precincts within
the city. This means that, as shown in Map 9, 1930 population density could
only be averaged over the available geographic boundary of the larger Minor
Civil Division.
By 1970, the census changed from the Minor Civil Divisions to Census
County Divisions. The new boundaries were also subdivisions of counties,
however, there were fewer districts with larger areas (Fig. 74). In these
CCD’s, the tabular data were separated by districts, with the population
numbers listed as a total for the district, and then listed by total city population within the district.70 For the districts which contained one or more cities,
population density, as shown in Map 10, was calculated for the areas within
city limits and separately for the areas outside the city limits with each
district.
In calculating population density for 1930 and 1970 in the WRB, we
calculated the total population density for each district that included areas
inside the WRB, and then used the WRB boundary to include only those
portions of the areas within the WRB (Fig. 75).
Benton County
Figure 73. Boundaries for census in
Benton County, 1930, 1970, 1990. In
1930, the Minor Civil Division
boundaries tended to be rectilinear
and were based on election precincts,
whereas in 1970 there were fewer
districts with larger areas.
PNW Ecosystem Research Consortium
Corvallis
1970
1930 MCD
1970 CCD
1990 Block
Monroe
1970
HUMAN POPULATION
Maps 9 & 10. 1930, 1970 Population Density
Saint Helens
Saint Helens
Colu
Colu
r
mbia Ri v e
r
mbia Ri v e
Scappoose
Banks
Wil
Wil
m
la
la
m
e
e
Fairview
r
ive
R
r
ive
R
Hillsboro
Forest Grove
Portland
tte
tte
Hillsboro
Portland
Beaverton
Gaston
m
Yam
h
Saint Paul
Woodburn
Gervais
Sheridan
Mt. Angel
Silverton
Dallas
Salem
Independence
Falls City
North Santiam
ett e .
R
Philomath
Mid
Stayton
San ti
am
R.
R.
North Santiam
Lyons
Gates
Mill City
Jefferson
Wil
la m
ett e .
R
River
Corvallis
Marys
Aumsville
Sublimity
Turner
Scio
Detroit
Idanha
R.
antia m
hS
ut
So
Albany
River
Wil
la m
te
amu
cki
Lu
R.
antia m
hS
ut
So
Marys
Monmouth
.
R
San ti
am
R.
R.
.
R
te
amu
cki
Lu
Scotts Mills
.
Clac k am as R
.
Clac k am as R
Salem
Dallas
Molalla
ng
di
Keizer
Silverton
Mo
la
Donald Aurora
Hubbard
Pud
R i ver
Pud
Estacada
Canby
So u t h
Willamina
Sandy
Newberg
R.
ill
Amity
m
R.
Molalla
ng
di
Oregon City
Tualatin
lla
So u t h
Dayton
R.
Woodburn
McMinnville
lla
Yam
h
Mo
la
R.
ill
Sherwood
Dundee
Lafayette
Carlton
Canby
McMinnville
n R.
C lacka
R.
Yamhill
Gresham
Tigard
Lake Oswego
as
Newberg
o r t h Yamhill R.
Sandy
R.
Oregon City
N
as
n R.
a ti
l
l
N
o r t h Yamhill R.
C lacka
a
Tu
a
Tu
a ti
R i ver
Lake Oswego
Albany
Lebanon
Corvallis
.
am R
nti
Sa
d le
Waterloo
Sodaville
d
Mid
am R
nti
Sa
le
ntiam R.
So uth Sa
Brownsville
ntiam R.
So uth Sa
.
Sweet Home
Halsey
Monroe
zie R .
McKen
Junction City
Mc K e n
zie R .
McKen
Coburg
Mc K e n
Springfield
Eugene
Veneta
zie
R.
Springfield
Eugene
Creswell
Mid
dle
Mid
d
Lowell le F
o
r
k
Fo
r
m
illa
W
te
Cottage Grove
et
R.
te
R.
Oakridge
Coast F
ork W i l l
am
et
m
illa
W
Cottage Grove
.
Junction City
k
City limits
River
R.
Coast F
ork W i l l
0
1 - 16
17 - 37
38 - 65
66 - 109
110 - 178
179 - 287
288 - 477
478 - 789
790 - 1246
1247 - 1781
1782 - 2393
2394 - 2989
2990 - 3535
3536 - 4027
4028 - 4521
4522 - 4965
4966 - 5409
5410 - 5866
5867 - 6296
6297 - 6746
6747 - 7182
7183 - 7668
7669 - 8192
z ie
Cala
poo
ia R
Harrisburg
.
Long Tom R.
Persons
per mi 2
Long Tom
R.
Cala
poo
ia R
e tt
eR
am
.
e tt
eR
.
N
69
Map 9. 1930 Population Density
Map 10. 1970 Population Density
S
Division
Boundaries
County Lines
and WRB
1930 Minor Civil
Division Boundaries
70
1970 Census County
Division Boundaries
Figure 74. 1930 Minor Civil Divisions and 1970 Census County Divisions.
Comparison of MCDs and CCDs shows larger census areas in 1970 than
1930.
Figure 75. Change in population density 1930-1970.
This map was constructed by
using a 1 mi2 grid superimposed on both 1930 and 1970
population density maps.
Areas decreasing in population density from 1930-1970
are shown in blue. Increased
density is shown in orange.
Urban cores are decreasing in
density while surrounding
suburbs are increasing.
Population growth in the
outlying areas and development of non-residential land
uses in city centers contribute
to change in densities. The
increased density in suburbs
and outlying areas is especially apparent in the corridor
along the Willamette River.
Willamette River Basin Atlas
2nd Edition
Change in
# people
per mi 2
-4570 - -3328
-3327 - -1991
-1990 - -1018
-1017 - -412
-411 - -176
-175 - 101
-100 - 55
-54 - -34
-33 - -20
-19 - 10
-9 - -1
0 - 19
20 - 43
44 - 70
71 - 114
115 -177
178 - 251
252 - 438
439 -769
770 - 1140
1141 - 1455
1456 - 1896
1897 - 2443
2444 - 3492
3493 - 5703
5704 - 13799
13800 - 41418
55