1H-Imidazo[4,5-c]quinolin-4-amines substituted at the 1-position with a substituent bearing a hydrazinobenzamide or hydrazinonicotinamide, a salt thereof, or a protected hydrazinobenzamide or hydrazinonicotinamide and conjugates made from such compounds are disclosed. Pharmaceutical compositions containing the compound or the conjugate, methods of making a conjugate, and methods of use of the compounds or conjugates as immunomodulators for inducing cytokine biosynthesis in an animal and for vaccinating an animal are also disclosed.