We have measured the left-right asymmetry for the inclusive production of π±, K±, and protons in proton-proton and proton-deuteron collisions at 11.75 GeV/c. The measurements, utilizing the polarized proton beam at the Argonne zero-gradient synchrotron, cover a wide range of kinematic variables [u between 0.6 and -1.5 (GeV/c)2 and x between 0.1 and 0.9 for meson production, t between -0.2 and -2.0 (GeV/c)2 and x between -0.25 and 0.75 for proton production]. There is considerable angular structure in the pion-production data but not in the kaon or proton processes. Proton production alone is clearly sensitive to the isotopic spin of the target particle. A simple phenomenological model of baryon-exchange dominance successfully relates the inclusive pion asymmetries to the asymmetries in backward pion-nucleon elastic scattering. A triple-Regge model for the inclusive proton asymmetries is also discussed.