Who did Obama choose as his running mate in 2008?

Most presidential candidates choose a potential vice president (sometimes called a "running mate") who has certain skills or experience the candidate feels will be helpful; the ideal vice president will enhance the abilities and skills the president is offering. In this case, Obama did not have a lot of foreign policy experience, so he chose Joseph (Joe) Biden, a long-time senator who had years of experience on congressional committees dealing with foreign policy.