Excelsior Henderson was formed when the Excelsior Motor Company of Chicago, founded in 1907, acquired the Henderson Motorcycle Company in 1917. Henderson was known for smooth inline four-cylinder engines, and the combined company built some of the largest and most powerful American motorcycles of its era. Production ended in 1931 during the Great Depression, but the machines built in those years left a lasting mark on American motorcycling history.

Excelsior Henderson is remembered for models such as the Super X, an advanced V-twin, and the Henderson four-cylinder machines prized for speed and refinement. The brand name was revived briefly in the late 1990s with a new Super X built in the United States before that effort ended in 2000. Original Excelsior Henderson motorcycles are now valuable collector pieces at major motorcycle auctions. At its peak the company was one of the strongest names in American motorcycling, competing directly with Indian and other builders of the period.

Excelsior Henderson workshop manuals cover the four-cylinder and V-twin engines, carburetion, ignition systems, clutch and transmission, brakes, and electrical details. Factory specifications and maintenance procedures are important for preserving these early American motorcycles and for running them at vintage events.

These manuals are mainly of interest to antique motorcycle collectors, restorers, and specialists in early American machinery. Because original machines are rare and valuable, accurate documentation is especially important for correct restoration and safe operation. Reproductions and specialist parts exist for some models, but the factory manuals remain the definitive guide to correct assembly and adjustment.