They came before Columbus Dr Ivan Van Sertima

Lecture given by Dr Ivan Van Sertima discussing African history.
Recorded in 1986 at Camden Town Hall, London.

http://video.google.com/videoplay?docid=-3924842503305971166#

for an further expansion on this work see

Phil Valentine: The Astro-Metric Timetable of the Olmec-Maya
http://tracker.concen.org/torrents-details.php?id=10187

warning: Phil valentine can be very insulting.