After 1850, the influence of the American settlers began to increase with the tribes of the Northwest, while that of the Hudson Bay Company declined. In 1853, Washington organized as a Territory, and in 1854, the U.S. government sent Governor I.I. Stevens, Colonel M.C. Simmons, and a few associates to make treaties with the Native Americans. On December 26, 1854, a treaty was made at Medicine Creek (presently McAllister) with the Puyallup, Nisqually and Squaxin Indians, together with a few small, associate tribes. Land for reservations was set aside for each of the tribes. The treaty was ratified soon after it was made and proclaimed April 10, 1855. The Puyallup's reservation was originally 1,280 acres, two years later recommendations were made to enlarge the reservation to 18,062 acres. Under provisions of the sixth article of the Medicine Creek Treaty and executive orders the reservation was enlarged in 1857.

Washington's first telegraph line paralleled Military Road that ran through the heart of Edgewood. Approximately 420 non-Native Americans resided in what is now Pierce County in 1858. The total value of property in Pierce County, including Puget Sound Agricultural Company and Hudson's Bay Company, was $749,000.00. The county had six stores, three schoolhouses, two churches and no practicing doctors. By 1862, 681 non-Native Americans were reported to be residents of Pierce County.  Evidence indicates that the first building on the North Hill (Surprise Lake) was a one-room log building formed as School District 27 in 1891. Mrs. Morris taught at the log school and is credited with naming the area Edgewood after her home town back east, located in Maryland.

The first official run of the interurban line from Tacoma to Seattle, by the way of the valley, was in October 1902. The State Spiritualists, who had six churches in Western Washington, had a summer camp at Edgewood that was purchased in 1903. In the early days, people came from Tacoma in interurban cars, got off at Jovita where they were met by horse and wagon, for the final leg of the trip to camp. Construction of a campground hotel began in 1927, and before completion a fire destroyed it in 1948.

The first formal, local government on the Hill was the Edgewood School District. Children were educated by the District in elementary school through junior high school, and then had a choice of attending one of three high schools in three other School Districts - Fife, Puyallup or Sumner. In the early 1960's, the State Superintendent of Public Instruction's Office implemented a policy - the County School District Reorganization Plan - that would phase out the non-high school Districts. The citizens in the Edgewood School District conducted a lengthy, spirited debate on which of the three other Districts to join; the vote resulted in the community splitting between the three Districts. Today, there are currently three elementary schools and one junior high school in the community, all administered by the Puyallup School District; the Fife and Sumner School Districts have facilities that are located outside the community.

The second formal government formed on the Hill was Pierce County Fire District #8, a volunteer department created in 1945 which officially began serving the community in 1947. This group of volunteers became the focal point of the community, having a three-member elected board of directors and levying a local property tax to finance both the purchase of equipment and the District's daily operations. The Fire District now has six full time staff, plus approximately 35 volunteers, serving the community.

In the late 1980's, the community was faced with land use issues as Pierce County and the Puget Sound region continued to grow. A community plan, the North Hill Plan, was formulated with the support of the Pierce County Council and County administration, together with the residents of the Edgewood community. In 1993, an incorporation effort was launched to provide the community residents with the authority of local control so they could determine their own destiny. The successful vote for incorporation was conducted in April, 1995. In September, 1995, the first City Council elections were held, with the 14 survivors of the primary election meeting in the finals. The seven persons elected - Dan Burgess, Terry Faherty, Rose Hill, Larry Mock, Eric Paige, John Powers and Sandy Schulz - formed the first governing body for the new City of Edgewood. This group selected Terry Faherty, a life-long resident of Edgewood except for his absence due to military duty, as their first Mayor.