Did a quick search and couldn't find this on apug. Hope it's useful to someone!
A video from Getty on artbabble on the Wet Collodion process.
" Invented in 1851, the wet collodion photographic process produced a glass negative and a beautifully detailed print. Preferred for the quality of the prints and the ease with which they could be reproduced, the new method thrived from the 1850s until about 1880."