Historic Horseshoes: March on Pavement Impressed Military of Value of Calks for Artillery Horses | Horse And Rider World | Scoop.it
In 1935, a battalion of the 16th Field Artillery marched from Fort Myer, Virginia to Pennsylvania. The horses that pulled the artillery were experimentally shod with toe-and-heel calked horseshoes to test the difference in wear over hard-paved roads.

Via Susie Blackmon