This studio, built in Greenfield Village, illustrates the first quick, inexpensive photographic process available on a large scale in America. Introduced about 1856, tintypes gained widespread popularity as keepsakes for Civil War soldiers and their families. With the development of the tintype, Americans began to accept photography as an inexpensive alternative to portraiture.
http://www.wrenscottage.com/gvm/village/tintype.php