Written by Working with over-time census data is challenging because of changes to block groups and tracts.
The National Historical Geographic Information System at the University of Minnesota provides Census files that have all been harmonized to 2010 tracts:
https://www.nhgis.org/documentation/time-series
The build returns an extremely well-structured and well-documented data file for all 72,000+ Census tracts.
--------------------------------------------------------------------------------
Codebook for NHGIS data file 'nhgis0001_ts_geog2010_tract'
--------------------------------------------------------------------------------
Contents
- Data Summary
- Data Dictionary
- Geographic Integration Methods
- Source Data
- Citation and Use
Detailed notes on time series design and comparability are available at:
https://www.nhgis.org/sites/www.nhgis.org/files/nhgis_time_series_tables.pdf
--------------------------------------------------------------------------------
Data Summary
--------------------------------------------------------------------------------
Time series layout: Time varies by column
Geographic level: Census Tract (by State--County)
Geographic integration: Standardized to 2010
Data measurement years: 1990, 2000, 2010
...
--------------------------------------------------------------------------------
Source Data
--------------------------------------------------------------------------------
Additional documentation on NHGIS data sources is available at:
https://www.nhgis.org/documentation/tabular-data
Table 1: (CL8) Total Population
Time series AA: Persons: Total
Year: 1990
Source geographic level: Block (by State--County--Tract)
Source dataset: 1990 Census: STF 1 - 100% Data
Source table: NP1. Persons
Universe: Persons
Variable: [ET1001] Total
Year: 2000
Source geographic level: Block (by State--County--Tract)
Source dataset: 2000 Census: SF 1b - 100% Data [Blocks & Block Groups]
Source table: NP001A. Total Population
Universe: Persons
Variable: [FXS001] Total
Year: 2010
Source geographic level: Census Tract (by State--County)
Source dataset: 2010 Census: SF 1a - P & H Tables [Blocks & Larger Areas]
Source table: P1. Total Population
Universe: Total population
Variable: [H7V001] Total
...
Diversities and Disparities Project
Similarly, the Diversities and Disparities project run by John Logan and colleagues have generated a free longitudinal dataset of harmonized Census variables from 1970 to 2010:
https://s4.ad.brown.edu/Projects/Diversity/Researcher/Bridging.htm