Harrisburg's twentieth-century boom led to the establishment of several architectural firms that supplanted Miller I. Kast and brought commercial modernism to the city. Lawrie and Green found a niche in public commissions, while Clayton Lappley was the principal commercial architect with a circuit of commissions that reached to Carlisle, Mechanicsburg, and Lancaster. Here he essayed a blonde brick and limestone tower notable for its streamlined verticality and its crowning octagonal cupola containing the elevator penthouses. Lappley also designed Market Street Trust at 1006 Market Street (1921).