US Lacrosse National Convention this Weekend By USIL Jan 10, 2007 - 1:01:16 PM US Indoor Lacrosse players, coaches and staff will be on hand at the 2007 US Lacrosse National Convention at Booth 237. The US Lacrosse National Convention will be held at the Pennsylvania Convention Center in downtown Philadelphia on January 11-14. Over 5,000 lacrosse enthusiasts attended last year's convention. This event has established itself as the largest educational opportunity for US Lacrosse member coaches, officials, and administrators in the world.