All matter, including galaxy clusters, galaxies, and their constituents follow orbits and flows driven by the net attraction of near and distant masses. The book presents the development of studies of peculiar motions along with discoveries in large-scale structure, the cosmic microwave background, baryonic oscillations, gravity waves, and their relation to current work on gravitation and dark matter.The results of peculiar motion measurements in the late 20th century are described as they were used to search for the dipole of the galaxy motions, a determination of cosmic density, and to compare with the cosmic microwave dipole, which led to the discovery of galactic flows and the Great Attractor. Newer detailed measurements from surveys in the 21st century have helped resolve the nature of these structures. Some prospects for future investigations are discussed.