Building Fort Knox required a slow, labor-intensive process of first preparing the site and then raising the walls. People, machines, and animals worked at removing earth, blasting ledge, and clearing rocks and soil before construction could proceed. Isaac Stevens, the first engineer in charge, reported that rock excavation began in 1846 with more than 75 men and several ox and horse teams working four months. Work stopped the next year for lack of funds, then continued for several months each year from 1848 through 1851. By the end of that period, more than 35,000 yards of stone had been excavated and moved. Most of this dark brown bedrock, Penobscot schist, was hauled to the waterfront and used to build the enrockment, a steep, massive rock-faced bank rising 75 feet from the river's edge to the fort's main level. Because the fort was built from the outside inward, the walls around the parade ground were completed last, and their archways and stonework stood as a final testament to the skills of the laborers, carpenters, stonecutters, blacksmiths, teamsters, and masons who built the fort. By 1855 or 1856, the enrockment was complete, and a long wooden inclined plane built in 1853 carried granite from the wharf to the main site; in 1856, Capt. John Kurtz reported that the front wall had risen to about the level of the casemate floors, while rock was probably being excavated for the barracks cellar. In the spring of 1863, work on the north, east, and west parade ground walls was finally moving rapidly after years of little or no funding, as Maine's successful appeal to the federal government brought increased funds during the Civil War to complete the state's forts and strengthen coastal and river defenses. Fort Knox's April 1863 payroll listed 6 carpenters, 2 engineers, 9 blacksmiths, 23 masons, 55 stone cutters, 4 teamsters, and 78 laborers; the master mason and master stonecutter earned $3.00 per day, while laborers earned from $.75 to $1.40 per day.