The Marx Convention will be on June 24 and 25th in Wheeling West Virginia. The show is held at the Kruger Street Toy & Train Museum. The show will be two days with talks and collectors selling items. You never know what you will find at the show. Also you will be able to visit museum and see their extensive collection of Marx toys.
Check out their web site for more details http://www.toyandtrain.com/convention.htm