One source of brief biographies for the first generation of Protestant missionaries in Siam is found in the "Vinton Book," a description of which is copied from the introduction to the book, below. The biographical sketches cover only missionaries connected with the Siam Mission of the American Board of Commissioners for Foreign Missions (ABCFM) and contain just dates and events. These sketches, however, provide information for missionaries who served only briefly in Siam and for whom there is little biographical information. I discovered this source by searching the Web for "congregational missionaries siam."
"Reverend John A. Vinton, then of South Boston, later of Winchester, Massachusetts, compiled in 1869 brief biographies of missionaries of the American Board from the beginning of the Board's history till 1869, writing them in longhand in a blank book.
"Mr. Vinton died November 13, 1877
The biographies were brought down to 1878 by Dr. Alfred 0. Treat.
From 1878 to 1886 the notices were prepared by Miss A.M.Chapin.
In copying the Vinton Book, we have divided it into [four] volumes.
Volume 1 covers the Missions in:-
ASIA: Eastern, China, Japan
ASIA: Southern, India and Ceylon