Smith is a common surname in the English language because of its original usage as an occupational surname, along with its adoption by several immigrant groups. The name Smith originally identified an ironworker, a common occupation in medieval England.
Smith derives from the Anglo-Saxon word "smitan," meaning "to smite" or "to strike." This leads some scholars to hypothesize that the surname was originally adopted by soldiers and warriors. Some speculate that those who were assigned to repair the original Smiths' armor later adopted the name as well. As the English language evolved, the Old English words "smio" and "smib" were used to identify a metalworker.
Once the surname became common in England, migration to what would eventually become the United States propagated the name there. Many early settlers bore the surname; one famous example is John Smith of Jamestown. Later in U.S. history, some slaves received the surname after being purchased by a master who had the surname of Smith; others adopted the name when emancipated. Other immigrants, including Germans with the Schmidt surname and Poles with the Kowalski surname, adopted Smith upon their arrival to the United States. As of 2000, Smith was the most common surname in the United States.