The Clayton-Tamm name is derived from the intersecting streets of Clayton Avenue and Tamm Avenue, which is the center of the neighborhood's business district.
The earliest development in the (not yet) neighborhood was by Charles Gratiot, who in 1785 requested use of the land from Spanish authorities in the French-owned land before the Louisiana Purchase "to cultivate wheat, hemp, corn, tobacco, etc., etc.", (Requoted from McCune Gill by Bob Corbett, 2000). The grant was formalized by the Spanish governor in 1798 and reaffirmed in 1808 by the US after the Louisiana Purchase. After Charles' Death his large land grant was divided into 12 strips and given as inheritance. Major growth in nearby Cheltenham neighborhood defined the region in the late 19th century as it developed into a coal and clay mining community (ultimately known as Dogtown). Growth was further accelerated by preparations and construction for the 1904 World's Fair, "The Louisiana Purchase Exposition."
While there are a number of theories as to why this neighborhood is known as Dogtown, the most credible account describes a group of coal miners working in what is today Forest Park. When the city acquired the land to build the park in 1876, these people found sparsely populated areas south of the new park and built shacks to live in as they found new work. In order to secure their ramshackle homes, many of the squatters used watchdogs, which would defend their territory.