Locating your ancestor in a census is relatively easy if an index exists.  Unfortunately, the 1930 census has been soundexed for only 12 states.  Only 21 states have an index for 1910.  Over 99 percent of the 1890 census was destroyed by fire in January 1921.  City directories bridge these gaps.  See the case studies below to learn how city directories complement census research.

Case Study #1: Locating David Goetz in the 1910 New York City federal census.
Comprehensive Guide to the 1930 census.

Case Study #1: Locating David Goetz in the 1910 New York City federal census.

The 1910 U.S. census for the state of New York, including all of New York City, is not soundexed.  Because there is no traditional soundex index to this census for New York, it is virtually impossible to locate an individual in New York City in 1910.  It would be too overwhelming to start searching page by page, which may work for a much smaller locale.  Because of this, another index was developed - one that cross-references street addresses to enumeration districts.  In order to use this index, an individual's address is needed.

In the 1910/1911 city directory for New York City (Manhattan and Bronx boroughs), David Goetz, an expressman, was listed at 476 Grand.  Using the street index for the 1910 census for New York City, 476 Grand was listed for E.D. 771 (this enumeration district covered 463 to 482 Grand).

Starting with the first page of E.D. 771, the enumeration district was searched page by page looking for the address of 476 Grand.  David Goetz was found at that address on page 15B of the E.D.  The occupation listed for him on the census (Moving House Expressman) matched the occupation listed for him in the city directory.