Actor and musician Gary Sinise discusses his decades-long mission to support military service members, veterans, first responders, and their families through visits, performances, and the Gary Sinise Foundation. He explains how his experiences with Vietnam veterans, his role as Lieutenant Dan, and the post-9/11 wars led him into deep service work, including hospital visits, base tours, mental wellness initiatives, and programs for families of the fallen. Sinise also shares the story of his son Mac's rare cancer, profound faith, and musical legacy, and how Mac's compositions now support the foundation's work and help the family process their grief.