The proton is a composite object made of fundamental, strongly-interacting quarks. Many of the features of the proton can be described by a simple picture based on three "valence quarks" bound by the exchange of gluons. Protons are much more complex objects, however, with the vast majority of their properties (mass, spin, etc.) dynamically generated by Quantum Chromodynamics. Those properties manifest themselves through a "sea" of gluons and quark-antiquark pairs. By measuring the Drell-Yan process, one is able to cleanly investigate the quark and anti-quark distributions of the free proton and a proton bound in a nucleus, where cold nuclear medium is expected to modify the quark distributions. 

E906/SeaQuest experiment, as the successor of a series of successful fixed target dimuon Drell-Yan experiment at Fermilab, will significantly extend the kinematic coverage and clearly resolve the ambiguities in light sea quark distribution inside nucleon and the quark behavior inside cold nuclear medium. E906/SeaQuest has been taking physics data since 2013, and will continue till the summer of this year. After that, the LANL-led E1039 experiment will replace the E906 targets with a new polarized proton (NH3) target and for the first time measure the sea quark Sivers function, to illuminate the origin of nucleon spin. In the meantime, new experiments at SeaQuest are also exploring the novel usage of the very high luminosity data from beam dump to search for dark photons/higgs through their weak coupling to standard model particles. In this talk, I will present the first preliminary results from E906 and also highlight the future prospects of the E1039 polarized Drell-Yan and the E1067 dark photon search programs.