 In 1993, Haynes joined the D.C. office of Jenner & Block as a partner.Upon moving to General Dynamics Corporation in 1996, Haynes was initially staff vice president and associate general counsel, and later general counsel for the company's Marine Group.In early 1999, Haynes spent four months as a volunteer in central Asia working on microcredit programs for Mercy Corps International, before returning to his partnership at Jenner & Block.