Census, Soundex

Using Soundex

Editor’s Note: The following article is an excerpt from Emily Croom’s bestselling Unpuzzling Your Past. 4th Edition Expanded, Updated and Revised, an invaluable guide which provides all the tools you need to begin your family research. More information about Ms. Croom’s book can be found at the end of this article.

In the following, Ms. Croom discusses how to utilize the Soundex code for genealogical research, which states have the information for specific census years, as well as issues you may encounter in your research.

The 1880, 1900, and 1920 federal censuses and parts of the 1910 and 1930 censuses are indexed by state using a code based on the sounds in surnames. This indexing system is called Soundex. It is most often available as microfilm of the cards on which basic census information was written . . . . The Soundex is especially useful when you do not know specifically where the family was living in the census year. It will tell you their county and community and where you can find them on the census.

One drawback of the 1880 Soundex is that it includes only households with children age ten and under. If Great-Grandpa’s children were already over age ten by 1880, you cannot find him in the Soundex unless he lived with a family that included young children.

States with 1910 Soundex (or Miracode, a Similar System)

Alabama          Illinois             Mississippi                 Pennsylvania

Arkansas         Kansas           Missouri                     South Carolina

California        Kentucky        North Carolina            Tennessee

Florida             Louisiana         Ohio                            Texas

Georgia            Michigan         Oklahoma                    Virginia

West Virginia                                                                                   

States with 1930 Soundex

  • Alabama
  • Arkansas
  • Florida
  • Kentucky (Bell, Floyd, Harlan, Kenton, Muhlenberg, Perry, and Pike Counties)
  • Louisiana
  • Mississippi
  • North Carolina
  • South Carolina
  • Tennessee
  • Virginia
  • West Virginia (Fayette, Harrison, Kanawha, Logan, McDowell, Mercer and Raleigh counties)

The Soundex Code

The Soundex coding system groups letters by the way they sound. Similar letters have the same code to account for spelling variations. In this way, the names Al(l)en, Al(l)an, Allene, Alleyne, Al(l)ain, Allien, Allyn, and other variants all have the same code: A450. However, other names with the same code would include names with the same group of letters: Almy, Alwin(e), and Allum. Even such dissimilar names as Carpenter, Corbin, Craven(s), Cherrybone, and Cherubini all have the same code number (C615) and appear together in the Soundex.

The code begins with the first letter of the surname. For the remaining letters, cross out all vowels (a, e, i, o, u) and y, w and h. With the remaining consonants, form a three-digit code. Code as one digit any double letters, such as tt, or rr, or consonants with the same code that occur together in a name, such as ck or sc. If you run out of key letters before you have the

required three digits, simply add one or more zeros. Practice coding your own family names. (See examples below.)

Soundex Code

Code Number Key Letters

1 b, p, f, v

2 c, s, k, g, j, q, x,

3 d, t

4 l

5 m, n

6 r

Examples of Soundex Coding

C A M P B E L L C514. C= initial letter. Strike vowels. Code M. PB

C 5 1 4 and LL are each coded as one digit.

R AY R000. R=initial letter. Strike A and Y. Add three zeros

R 000 since there are no other letters to code.

SCHWENNEKER S526. S= initial letter. Initial SC is treated the same as

S 5 2 6 a double letter inside the word. Strike Vowels, H and

W. Code NN once, and code K and R.

ROBERTSON R163. R= initial letter. Strike vowels. Once you have

R 1 6 3 a three-digit code, disregard the remaining consonants.

Some census entries show the surname written incorrectly, spelled with C instead of K, minus the final syllable, spelled with an added final e or s, spelled phonetically instead of correctly, or misunderstood for another name entirely. If your research names can have several spellings (and most can), code the usual variations and look for them all in the Soundex or other index. Soundex codes that are almost the same, such as 450 or 452, are often grouped together as “mixed codes.” Sometimes prefixes such as von, van, de, de la, and le are omitted in coding. Be aware that some names and their common variations will have different Soundex codes because of different initial consonants or subtle changes in spelling, as in the chart examples below.

Examples of Soundex Problems

Names that are similar, with different initial letters:

Carson C625 Riggins R252 Ebert E163

Garson G625 Wiggins W252 Hebert H163

Names that are confused with each other and have different codes: 

Garner G656 Larson L625 Saddler S346

Gardner G635 Lawson L250 Sandler S534

Rich/Richey R200 Robinson R152 Carson C625

Ridge/Ritchie R320 Robertson R163 Carlson C642

Watters W362 Harrell H640 Finch F520

Walter(s) W436 Harold H643 French F652

When you determine the Soundex code that applies to your focus family and any variant spelling that may send you to a different code, you are ready to get the microfilm. You would choose for Gardner, for example, the 1920 Soundex for Kansas for G635 (year, state, code).

When you find the family on the Soundex microfilm, write down these references to your family in the census itself: the county (you already know the state), enumeration district, page (sheet), and line number that begins the family listing.

You can also start your extraction of the information, as the household members, relationships, and ages are normally given on the Soundex cards. With this done, you can move to the census microfilm. Reading the Soundex does not take the place of reading the census; the Soundex gives only partial information.

To read more from Emily Croom, please check out her book, Unpuzzling Your Past. 4th Edition Expanded, Updated and Revised, which contains: tips for getting the most from names, dates, and family traditions; suggestions for using vital records of births, marriages, and deaths ; keys to census records, and all state and federal records; tools for using county courthouse records, including wills, deeds, and court records; discussions of church, cemetery, and newspaper sources; illustrations, charts, sidebars, and study lists for further reference; and blank forms, including a five-generation chart, family group sheets, and census forms covering the years 1790 to 1930.

Image Credit: Almon Brown Strowger in the 1910 US Census, By US Census [Public domain], via Wikimedia Commons.


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