In this presentation, members of the Compass Project discuss ways to support underrepresented undergraduates in physics, especially at the critical freshman transition. The data presented is in the context of The Compass Project, a program created at the University of California, Berkeley in 2006.  Drawing on physics education research, the project had two major goals in creating a two-week summer program for incoming freshman:  building community and helping students develop productive beliefs about what physics is and how to learn it.  Recently, an innovative semester-long course on physics problem-solving was developed to help the Compass students develop their critical thinking skills (and continue to build community) throughout the academic year.  Starting with a first seed group of eleven students, the project members have mentored and encouraged undergraduates as they continue to make a positive impact on the Berkeley physical science departments by bringing other students into the Compass community, volunteering at inner-city schools, and even running a lecture series aimed at an undergraduate audience.