Directly imaged planets and brown dwarfs are key tools for studying the formation, evolution, and atmospheric physics of wide-separation substellar objects. Dynamical masses of these objects are especially valuable, as they enable robust tests of cooling models. However, imaging campaigns have been limited by the low occurrence rate of long-period planets and brown dwarfs capable of detection with current facilities. As a result, fewer than 20 exoplanets with separations between 5 and 100 AU have been imaged, and only five have direct mass measurements. Our goal is to overcome these low occurrence rates and deliver new substellar companions with dynamical mass measurements by targeting stars exhibiting small proper motion differences between Hipparcos and Gaia that point to the presence of unseen substellar companions. Over the past two years, we have launched a systematic high-contrast imaging survey with Keck/NIRC2, SCExAO/CHARIS, and VLT/SPHERE of the accelerating stars most likely to harbor long-period giant planets and brown dwarfs. In this poster, I will present an overview of our program, our novel approach to efficient target selection, and exciting new planet and brown dwarf companions discovered through this survey.