McGrew writes that this vertical script was introduced in c1879 by the Cincinnati TF,¹ which joined ATF in 1892. It was apparently discontinued after the catalog of 1900.
In the meantime, Barnhart Bros. & Spindler also acquired it; specimens are shown in the 1893–1894 Pony Book and regularly thereafter. It was renamed Engravers Upright Script for the 1925 catalog (thank you, Robert!).¹
Letterforms of the swash caps match the plain ones. In some commercial specimens, the ornamentation appears to be printed in gray, which implies that it was intended for multi-color work.
¹McGrew, M. (1993): American Metal Types of the Twentieth Century (Second, Revised Edition), page 133. Oak Knoll Press, New Castle, DE.