The Housing Authority of Portland was created in 1941 in response to the urgency of war preparations and the needs of the thousands of people who moved to Portland to help build ships for the military and work in other war-related industries.

The need for housing for workers became apparent in the summer of 1941, when Portland and Vancouver were transformed into a shipbuilding center. Thousands of workers and their families were unable to find housing and had to live in hastily constructed shantytowns. In response, the Portland City Council created HAP on December 11, 1941, just four days after the Japanese attacked Pearl Harbor. Its mission was to rebuild the city's sprawl of rundown housing and to create new housing for the workers who were arriving from all over the country.

In response to the housing shortage, shipyard industrialist Henry Kaiser purchased land on the Columbia Slough and worked with the U.S. Maritime Commission in 1942 to build apartment buildings in what would become Vanport City. HAP, left out of the initial negotiations, agreed to manage the project. At about the same time, HAP started building Columbia Villa, a large housing development in North Portland, as well as other housing around the city. In just two years, the agency reportedly provided housing for seventy-two thousand people who worked in the shipyards and related industries.

Like all public housing authorities, HAP owns and operates housing that is subsidized by the U.S. Department of Housing and Urban Development. One major HUD program is Section 8 rent assistance, which HAP offers to thousands of people in the Portland area through a voucher program. Section 8 tenants pay only a portion of the rent owed, and HAP pays the rest.

HAP describes its challenge as helping "improve the prospects of the community's most vulnerable citizens" in times of economic hardship. In its mission statement, HAP states that it "has a special responsibility to those who encounter barriers to housing because of income, disability or special need."

Oversight for HAP comes from a nine-member appointed board of commissioners, which appoints the executive director. In 2008, HAP provided affordable housing to more than thirty-three thousand people. In 2011, HAP changed its name to Home Forward.