Series I. Correspondence has been divided into two subseries, Outgoing and Incoming. Most of Snyder's correspondence appears to have been generated by Snyder to obtain information and consult with other experts in her field while she was writing various books and articles. There is very little personal correspondence. All correspondence has been place in alphabetical order by correspondent. Each correspondent's letters are arranged chronologically. Major correspondents by volume include Richard J. Eaton, Eugene Eisenmann, Richard French, Noel Howe, James P. Pool, ad Alexander Wetmore.