The Keepers of the Trail — Joseph Altsheler

This is the third book in the Young Trailer series. Henry Ware as come into his own as a borderer - bent on protecting the new towns of Wareville and Marlowe. Along with Shif'less Sol, Paul Cotter, Long Jim, and Silent Tom, Henry matches wits with the Shawnee army marching on Kentucky. The Shawnee are joined by English soldiers with canons and the renegades Braxton Wyatt and Blackstaffe. Using only their wits and woodlore, the five must prevent the canons from reaching the towns. Using their deadly accuracy shots and the superstition of the indians, the Five must win the day.