The forced van der Pol equation is one of the classical examples in dynamical system theory. Nonetheless, the bifurcations of this system have not been thoroughly studied. This lecture will give describe new results of Kathleen Hoffman, Warren Weckesser and myself that are based upon investigation of the slow flow associated with the van der Pol system. We produce a global bifurcation diagram for the slow flow that encompasses the solutions of the system without canards.