The OA was founded during the summer of 1915 at Treasure island, the Philadelphia Council Scout camp. Treasure Island was part of the original land grant given to William Penn by King Charles II of England. The camp was located on a 50-acre wooded island in the Delaware River between New Jersey and Pennsylvania, 30 miles upriver from Trenton and 3 miles from Point Pleasant, Pa.  Historical records show that it was an early camping ground of the Lenni Lenape or Delaware Indians.

In May 1915, a young man named E. Urner Goodman was selected to serve as summer camp director of Treasure island. Another young man, Carroll A. Edson, was appointed assistant director in charge of the commissary.  Both men were 24 years old.

Goodman had been a Scoutmaster in Philadelphia and had considerable experience in Scouting and camping. Edson was a graduate of Dartmouth College and had also been in Scouting for several years. After their appointments were announced, they spent many hours together planning their summer camping season, and both did considerable reading and research to better prepare themselves for their new responsibilities.

Among the books Goodman read, several were about camping. One of these that impressed him the most, a book dealing with summer camp operation, contained a description of a camp society that had been organized at a camp to perpetuate in traditions and ideals from season to season. Goodman and Edson agreed that they wanted to establish a similar society at their camp. They wanted some definite form of recognition for those Scouts in their camp who best exemplified the spirit of the Scout Oath and Law in their daily lives. Since the Delaware Valley was rich in Indian tradition, and the island had been used in early times as an Indian camping ground, it seemed only natural to base this society, this brotherhood of honor campers, on the legend and traditions of the Delaware Indians.

Shortly after it had been announced that he was selected to serve as assistant camp director, Carroll Edson went home for a weekend visit. During that visit, he attended a meeting where Ernest Thompson Seton, Chief Scout of the BSA, was speaking. Seton described how, when organizing an earlier youth movement called the Woodcraft Indians, he had much success by utilizing Indian ceremonies at camp. This crystallized Goodman and Edson's idea of using the lore and legends of the Delaware Indians in their new brotherhood.

As a result, they prepared a simple yet effective ceremony that, in turn, led to the organization of what was later to become known as the OA. It was agreed from the beginning that the procedures and programs of the organization were to be based on the ideals of democracy, in their initial decisions, Goodman and Edson reflected those ideals by planning to elect members into the first lodge from the troops encamped at Treasure Island. Thus, from the beginning, a unique custom was established in that members were elected by non-members. There has been no change in this since that time. The original name, Wimachtendienk, Wingolauchsik, Witahemui, was suggested by Horace W. Ralston, a Philadelphia Scouter.  Ralston and Horace P. Kern had done most of the research on the Delaware Indians.

Soon after camp opened, Goodman explored the island in order to find the most appropriate setting for the ceremonial ground. He selected a site in the south woods of the island, far removed from the ordinary activities of camp, and Edson agreed that it would be an ideal spot. It was considerably off the beaten path, and because of its location was an excellent site.

The site chosen was a natural amphitheater formed by a ravine in dense woods. There was a clearing with sloping ground on one side, which lent itself well to spectator seating. The site was cleared of brush and a path cut through thick underbrush from the camp to the site.

Friday, July 16, 1915, dawned bright and clear on Treasure island. In addition to the heavy heat that often hangs over the valley of the Delaware, there was something else in the air. It was all almost indescribable feeling of expectancy and mystery. By sundown the air was charged with a tense excitement. Those who were present always remembered the first induction into what is now known as the OA.

As darkness fell, the campers were lined up in single file by Harry Yoder, who acted as guide and guardian of the trail. In total silence the campers followed the guide by a roundabout route through the woods to the site of the council fire. The path led down a small ravine across which lay an old fallen tree. The boys were unaware that they were approaching the council fire until suddenly it was revealed. It was built in a triangular shape. Behind it, in long black robes, stood the cofounders of the OA--E. Urner Goodman, Chief of the Fire, and Carroll A. Edson, Vice-chief of the Fire. The Chief of the Fire wore on his robe a turtle superimposed upon a triangle. denoting leadership, and the Vice-chief of the Fire, then called Sachem, wore a turtle without the triangle. (The turtle is the totem of the Unami Lodge.)

The original ceremony was quite different from that which developed later. There were three lessons taught that night:

1. The candidate attempted to encircle a large tree, individually, with outstretched arms. Having failed, he then was joined by several of the brothers who together had no difficulty encircling the large tree, thus teaching lesson No. 1, Brotherhood.

2. The candidate was directed to endeavor to scale a steep bank at the edge of the council ring. Failing in this, he again was assisted by the brothers, with whose help he was able to climb the elevation, thus teaching Service.

3. The candidate then was given a bundle of twigs and told to place some on the council fire, where the twigs caught fire and blazed brightly thus showing Cheerfulness.

In the first year, 25 members were inducted into the Brotherhood. In the original plan there were two degrees; the first was much like a combination of the Ordeal and Brotherhood memberships, and the second an early version of the Vigil Honor

To perpetuate the brotherhood, a membership meeting was held on November 23, 1915. George W. Chapman, the first lodge chief of Unami Lodge, served as chairman of the organization committee. This meeting marked the first formal founding of the OA. Goodman and Edson served as advisers to the committee.

By 1917, news of the organization, Wimachtendienk, Wingolauchsik, Witahemui, spread to other Scout camps and inquiries began.  Goodman spoke to many interested Scouts and Scouters, and as a result, lodges were established in N.J., Maryland, N.Y., and Illinois.

From 1915 until 1921 the Order grew slowly. World War I kept Scouts and leaders busy with many other problems and projects. In 1921 steps were taken to establish the Order on a national basis. The early years had produced sufficient experience to form a foundation on sound basic polices.

The first national convention was held on October 7, 1921, in Philadelphia, at which a national lodge was formed, composed of four delegates from each of the local lodges. This group adopted a constitution and a statement of policies. Committees were appointed to develop plans for making the Order effective as a national honor campers' brotherhood.

Following the convention there was a steady growth in lodges and membership in 1922, after the national lodge meeting at Reading, Pa., the OA became an official program experiment of the BSA.

For several years conventions of the national lodge were held annually. After 1927, they were held at 2‑year intervals. During the Philadelphia convention of 1929, it was suggested that the Order become an official part of the BSA and a component part of its program.  At the session of the national lodge in 1933, held at the Owasippe Camps of the Chicago Council, this proposal was made and ratified by the delegates.

On June 2,1934, at the National Council Annual Meeting in Buffalo, NY, the OA program was approved by the National Council.

In May 1948, the Executive Board, upon recommendation of its Committee on Camping, officially integrated the OA into the Scouting movement. The Order’s national lodge was dissolved and supervision shifted to the BSA.

The executive committee of the national lodge became the National Committee on OA, a subcommittee of the National Committee on Camping and Engineering, and a staff member was employed as national executive secretary in the 1974 reorganization of the BSA, the National OA committee became a subcommittee of the National Boy Scout Committee.  In 1998, the Order became recognized as Scouting's National Honor Society.

The growth of the OA through the years has never been based on an aggressive promotional plan. It came about because councils believed in the ideals expressed by the Order and voluntarily requested that lodges be formed.  The soundness of providing a single workable honor campers' brotherhood, rather than many, is evident.  More than 1 million Boy Scouts and Scouters have been inducted into the Order during the past 85 years.  The OA has more than 176,000 members located in lodges affiliated with approximately 327 BSA local councils.