Verichrome was made by Wratten & Wainright in the UK and introduced around 1907/8 it wasn't fully Panchromatic but it wasn't Orthochromatic either, George Eastman bought Wratten in 1913, partly to get Mees to head up two new Kodak Research facilities, Rochester & Harrow.
Eastman also wanted the Wrattnen - Mees & Sheppard's expertise in colour sensitisation, a consequence was Kodak continued making Verichrome, Verichrome Pan was very much later in 1956.
Plus -X was introduced along with Pan-X, Super-XX as part of a new range of films in 1938, followed by Tri-X a year later, these Kodak films were competitors to the Ilford/Selo F.P., Double-X, H.P.2 range, still around as Pan F, FP4+, HP5+.
Ian