Creating Spaces for Historical Data

Michael RatcliffeGeographic Standards and Criteria Branch

Geography DivisionUS Census Bureau

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Research Problem

Baltimore Ecosystem Study researchers needed historical demographic data for areas in which they were collecting data about the physical environment over a 200 year period.

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Challenges for researchers• Obtaining historical demographic data at

suitable geographic scales, particularly for small geographic areas;

• Developing a framework of small geographic areas for analysis of population distribution and demographic change over time;

• Relating historical demographic data to environmental and other information.

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19th Century Census Geography

• Counties• Minor civil divisions • Incorporated places• Wards• Enumeration districts• Sanitary districts

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Sources of Historical Geographic Area and Demographic Information• Decennial Census Manuscript Forms

– Header on each form has space to list state, county, county subdivision, and post office

• City and County Atlases– G.M. Hopkins, 1870s– Hexamer and Locher, 1860s and 1870s

• Fire Insurance Maps– Sanborn and Company– Hexamer, Ernest, and Son

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G.M. Hopkins, Baltimore County Atlas, 1876

7Source: S. Hinman, 2002

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Methodological Approaches

• Digitize geographic entity boundaries from historical maps

• Build a spatial framework using current census geographic areas

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Reisterstown Census Tracts

4044.01

4045.014045.02

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Census Tracts and 1870s Reisterstown

Tract 4045.01Tract 4045.02

Tract 4044.01

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Population by Sex and Race Upper Gwynn’s Falls Watershed, 1870

Table 1. Population by Sex and Race, by Post Office: 1870.

Post Office

2000 Census Tracts

Approximate 1870 Census

Population

Geocoded 1870

Census Population

White Males

White Females

Black Males

Black Females

Mulatto Males

Mulatto Females

Upperco and Woodensburg

4046 4044.01 1,225 572 189 197 34 33 9 10

Reisterstown

4042.01 4044.01 4044.02 4045.01 4045.02 4048 1,400 216 90 113 4 9 0 0

Source: 1870 Census, unpublished manuscript forms; G.M. Hopkins, 1877.

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Age and SexUpper Gwynn’s Falls: 1870

Table 2. 1870 Age and Sex by 2000 Census Tracts.

Post OfficeCensus Tracts

Geocoded 1870 Census

PopulationUnder 18

years18 years and over Males Females

Sex Ratio

Reisterstown 4042.01 59 29 30 29 30 96.7

Reisterstown 4044.01 35 14 21 18 17 105.9

Reisterstown 4045.01 39 14 25 22 17 129.4

Reisterstown 4045.02 84 47 37 25 58 43.1

Woodensburg and Upperco 4046.00 472 199 273 234 238 98.3

Source: 1870 Census, unpublished manuscript forms; G.M. Hopkins, 1877.

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Value of Personal and Real PropertyUpper Gwynn’s Falls, 1870Table 3. Value of Personal Property and Real Estate, by Post Office: 1870.

Value of Personal Property Value of Real Estate

Post Office

2000 Census Tracts Median Mean Median Mean

Upperco and Woodensburg

4046 4044.01 $500 $2,938 $3,000 $7,270

Reisterstown

4042.01 4044.01 4044.02 4045.01 4045.02 4048 $125 $782 $300 $5,319

Source: 1870 Census, unpublished manuscript forms; G.M. Hopkins, 1877.

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17(source: S. Hinman, 2002)

18(source: S. Hinman, 2002)