To find an individual name among the millions listed in the 1900 and 1910 censuses. you will use an indexing and filing system called the Soundex. The Soundex is a coded surname (last name) index based on the way a surname sounds rather than the way it is spelled. Surnames that sound the same but are spelled differently. like SMITH and SMYTH. have the same code and are filed together. The Soundex coding system was developed so that you can find a surname even though it may have been recorded under various spellings.

To search for a particular surname. you must first work out its code. Every Soundex code consists of a letter and three numbers. like S650. The letter is always the first letter of the surname. The numbers are assigned to the remaining letters of the surname according to the Soundex coding guide.

Most surnames can be coded using the following four steps. For names with prefixes. double letters. or letters side by side that have the same number on the Soundex coding guide. see "Additional Rules" on