Wide ranging potted history of snowshoeing and explanation of types of traditional snowshoes reprinted below, via GV Snowshoes.
In Paddle-to-the-Sea the Nipigon area boy sports the spear shape shoes as below, which jibes with notes from above.
In 1915 the first International Snowshoe Convention was held in Lewiston, Maine; and that same year the American Snowshoer's Union was founded. This union functions in a manner similar tn the Canadian Snowshoer's Union by furnishing support and guidance to slightly over twenty member clubs located in Maine, New Hampshire, Massachusetts, and Connecticut. -via Prater, G., & Felkley, D. (2002). Snowshoeing: [from novice to master]. Mountaineers outdoor expert series. Seattle, Wash: Mountaineers Books.
Finally, some pics below from the Life Archive, a 1950 shoot at the International Snowshoe Convention, in Lewiston, ME. This photographer Joel Yale seems to crop up a lot in my Life searches... off the beaten track stuff.