on the last friday before the primary, senator obama spoke on independence mall in philadelphia, pennsylvania, to a crowd of more than 35,000, the largest audience yet drawn by either candidate during the campaign. the crowd was nearly twice what had been projected and spilled over into nearby streets. the next day, obama conducted a whistle stop train tour from philadelphia to harrisburg, drawing a crowd of 6,000 at a stop in wynnewood and 3,000 at a stop in paoli. on monday, sen. obama held the final events of his pennsylvania campaign in scranton, mckeesport and at the university of pittsburgh's petersen events center.