How to Use Soundex/Miracode for United States Census Records

The Soundex system is a method of indexing names phonetically. Although Soundex codes are used today in many genealogical sources, the system is best-known as the method of indexing the U.S. Federal Census for the years: 1880 (families with children under ten), 1900, 1910 (21 states), 1920 and 1930 (13 states). This guide describes how Soundex codes are derived and how to use the system to locate persons in the census records.

The Soundex Code

1880 Census - Special Instructions

1910 Census - Special Instructions

1930 Census - Special Instructions

Using the Soundex Index to Locate Census Records

What about other census years?

What about the 1890 census?

The Soundex Code

The Soundex index uses a phonetic coding system that indexes names by eliminating some letters and substituting numbers for other letters.

To develop the soundex equivalent of a name, follow these guidelines and the subsequent rules:

The Soundex code consists of a letter and three numbers. The letter is always the first letter of the surname. The three numbers in the Soundex code are derived by coding certain consonants in the name (called "key letters") in the order in which they appear, according to the following chart and the subsequent rules:

B F P V ___________________________1

C G J K Q S X Z ____________________2

D T ________________________________3

L __________________________________4

M N ________________________________5

R __________________________________6

No consonants ______________________0

SUBSEQUENT RULES:

1. Disregard the consonants W, H, and Y and the vowels A, E, I, O, U.

2. When 2 or more of the same key letters (or their number equivalents) come together, they should be treated as ONE key letter.

EXAMPLES:

Sheppard S-163

Sacks S-200

3. A key letter or its equivalent immediately following an initial letter of the same value should be disregarded in coding.

EXAMPLES:

Schebowitz S-132

Scklar S-460

4. Key letters or their equivalents separated by H or W are coded as one key letter.

EXAMPLES:

Sokwzy S-200

Schkolink S-452

5. When a repeated key letter or its equivalent is separated by an A, E, I, O, U or Y, the key letters or their equivalents are considered separately.

EXAMPLES:

Staten S-335

Simone S-550

6. Some names do not contain any of the six key letters or their equivalents - that is they have only vowels A, E, I, O, U or W, H, Y, after the first letter of the name.

EXAMPLES:

Shea S-000

Lee L-000

Be sure to check alternate spellings that could change the Soundex code. The name "Kane", for example, should be checked under both K-500 and C-500 ("Cain").

1880 Census - Special Instructions

The Soundex index for 1880 was a partial index only. Although all households were counted in the actual census, the Soundex index only includes households with children under the age of ten. To locate households in the census which were excluded from the Soundex index, you may use sources such as city and county directories to identify the town or locality. You can then use the 1880 Enumeration District Descriptions microfilm at Clayton to locate the section of the census for that locality. You can also use the every-name index created by the LDS Church, this index is available in Clayton Library on CD-ROM or you can access it at on the Internet at www.Ancestry.com or www.familysearch.com.

1910 Census - Special Instructions

Only 21 states in the 1910 census were soundexed. To locate households in states which were not indexed, you may use sources such as city and county directories to identify the town or locality. You can then use the 1910 Enumeration District Descriptions microfilm at Clayton to locate the section of the census, or you can use the indexes available through the Heritage Quest or the Ancestry databases. Both databases are paid for by Houston Public Library and you can access the Heritage Quest database from home using your HPL PowerCard, but you need to come into one of the branches of Houston Public Library to use the Ancestry Library Edition database.

There are two types of soundexed indexes for 1910: Soundex and Miracode. The Miracode index uses the same phonetic code and abbreviations as the Soundex system, but the method of recording the census page reference is different. Both index cards list county, volume, ED, and the sequential family number assigned by the census taker. The Miracode card is computer generated, while the Soundex card is handwritten.

Miracode indexes are available for the states of Arkansas, California, Florida, Illinois, Kansas, Kentucky, Louisiana (New Orleans and Shreveport only - all other locations are Soundex), Michigan, Missouri, North Carolina, Ohio, Oklahoma, Pennsylvania, Virginia, and West Virginia.

Soundex indexes for 1910 are available for Alabama, Georgia, Louisiana (except New Orleans and Shreveport, which are on Miracode), Mississippi, South Carolina, Tennessee, and Texas.

1930 Census - Special Instructions

Only 12 states in the 1930 census were soundexed. To locate households in states which were not indexed, you may use sources such as city and county directories to identify the town or locality. You can then use the 1930 Enumeration District Descriptions microfilm at Clayton to locate the section of the census, or you can use the indexes available through the Heritage Quest or the Ancestry databases. Both databases are paid for by Houston Public Library and you can access the Heritage Quest database from home using your HPL PowerCard, but you need to come into one of the branches of Houston Public Library to use the Ancestry Library Edition database.

The 1930 Soundex index cards list county, volume, ED, and the sequential family number assigned by the census taker.

Clayton has the 1930 Soundex indexes for Arkansas, Louisiana, and West Virginia. We also have some scattered rolls of Soundex microfilm for some of the other states that were Soundexed for 1930.

Using the Soundex Index to Locate Census Records

Using the soundex code as determined above, consult the Soundex or Miracode index for the appropriate state and census year. Index cards are arranged by soundex code and then by the first name of the head of the household. If there are very few cards for a soundex code, you may find several different codes interfiled (This is called mixed codes by the National Archives). If your code falls in this category, a very careful reading is necesssary.

When you have located the Soundex or Miracode index card for the household in which you are interested, copy the following information:

COUNTY:

ED (Enumeration District):

SHEET NUMBER:

LINE/FAMILY NUMBER:

(**special note: if using 1910 or 1930 Soundex or 1910 Miracode, the last number given is the family number.)

With this information, you can then locate the census microfilm for the appropriate county and year, locate the enumeration district within the county, and find the household.

What about other census years?

Clayton Library has all available federal census records for 1790 through 1920, and some states for 1930. For 1790 through 1870, book and CD-ROM indexes are available which provide the county and page number on which the household can be found. Most book indexes list only the name of the head of household. There are some book indexes available for 1880, 1900 and 1910. To see the list of census indexes available at Clayton Library click here.

What about the 1890 census?

The 1890 census was almost completely destroyed by a fire in the 1920's; only a few schedules survived for the entire country, and these are available on microfilm at Clayton Library. There is a single nation-wide index to names in the surviving 1890 census fragments. The index is also on microfilm and is located in Clayton's microfilm drawers right in front of the 1890 census rolls. Clayton Library has a number of sources to help researchers to "bridge the gap" between the 1880 and 1900 census years, including city and county directories, the "1890 Special Census of Union Veterans and Widows", property tax records, and other sources.