The fortress was located on Washington Street, three quarters of a mile above the Ohio River. It consisted of 14 two-story houses arranged in the form of a hollow square, which measured 180 feet on a side. At each corner of the square stood a blockhouse with projecting upper story. Loopholes were cut in the projecting floor for showering bullets on Indian attackers. The entire fort was constructed of poplar planks four inches thick and 18 to 20 inches wide, which men hewed and whipsawed from the huge poplar trees that grew along the Muskingum. In one of the fort’s houses, which became Rufus Putnam’s home after the fort was dismantled, and which is now part of Campus Martius Museum, can still be seen the original timbers and form of construction. In the timbers, hewn in pre-determined shapes, were stamped Roman numerals, and by matching corresponding numbers, the artisans of that day were able to assemble the timbers into complete and substantial structures.
The blockhouses and part of the dwellings were built at the expense of the Ohio Company. On July 21, 1788, the directors ordered that carpenters be employed at half a dollar a day and one ration to complete the blockhouses, and that laborers be paid seven dollars per month and one ration per day. It was provided
“That a Ration consists of 1½ [lbs.] of Bread or Flour.
“1 lb. of Pork or Beef, Venison or other meat equivalent.
“1 Gill of Whisky.
“Vegetables.”
The complete structure contained 72 rooms. When the Indians finally went on the war path, the inhabitants constructed three lines of defense outside the fortress. A row of palisades sloped outward to rest on rails, a line of pickets stood upright in the earth 20 feet beyond the palisades, and a barrier of trees with sharpened boughs formed the first defense. Ammunition, cannon, and spears were stored in convenient places. The northeast blockhouse was used for religious meetings and sessions of the courts. At the outbreak of the Indian Wars in 1791, Campus Martius became the principal refuge of the people in Marietta. Of it, Putnam, who had built West Point and many other Revolutionary War fortifications, wrote that it was the finest fort in the United States.
While Campus Martius was being constructed, the survey was continued, the crops were planted and cabins erected and new settlers arrived. When John May arrived with a party of 11 men on May 26 and was invited to dinner by General Josiah Harmar, he was served, according to his diary, “beef a la mode, boiled fish, bear-steaks, roast venison, etc., excellent succotash, salads, and cranberry sauce.” Venison sold for two cents a pound and bear meat at three cents. May was surprised to see in Doughty’s garden an orchard of apple and peach trees and “cotton growing in perfection.”
Varnum arrived with a company of 40 settlers on June 5. Among them were James Owen and his wife, Mary Owen, the first woman who settled in the community. The settlers were so industrious that by June 20, 132 acres had been planted in corn in addition to large fields in potatoes, beans, and other vegetables.
As soon as the pioneers had provided shelter for themselves, they organized a temporary government to insure order and safety until the arrival of the officers of the Northwest Territory. On June 13 at an informal meeting of the directors and agents of the Ohio Company, it was decided that the directors present should act as a board of police to draw up a set of laws for the community. Colonel Return Jonathan Meigs was appointed to administer them. At the first official meeting of the directors the board of police was confirmed. The regulations provided for cleanliness, health, decency, safety, and moral conduct. Military guard was established. If any persons arrived who were not stockholders in the Ohio Company, the board of police was empowered to decide whether or not they should be permitted to stay. Settlers were required to carry arms during their work in the fields. No one was allowed to trade with the Indians without permission from the board or from Fort Harmar. Punishment for violation of the laws was to consist of either labor for the public, or expulsion. As evidence of the orderly conduct of the settlers it has been pointed out that in three months there was only one difference, and that was compromised. On July 4 the board of police nailed these temporary laws to the smooth trunk of a large beech tree near the mouth of the Muskingum.