Portland is on a bluff overlooking Nueces Bay in southeastern San Patricio County. The town was the dream of John G. Willacy, who merged the New England Land Company of Portland, Maine, the New England Real Estate Company, and the Portland Harbor and Improvement Company of Wichita, Kansas, into a working unit and purchased 1,920 acres of land from the Coleman-Fulton Pasture Company in 1891. A twenty-room hotel was built to prepare for the sale of lots that took place in July 1891. The steamer Mascot was chartered to bring customers from Corpus Christi across the bay, and the San Antonio and Aransas Pass Railway ran special trains to accommodate the crowds. Lots worth more than $48,000 were sold during the first two days, and the Cleopatra was chartered to bring guests to a dance in the new hotel. By 1892 the population had reached 500. W. A. McHarry, with Darius C. Rachal, Sidney G. Borden, and George Kleespies, formed a forwarding company that built a 1,200-foot wharf. A post office was authorized on March 9, 1891, with Walter Willett as the first postmaster. Business was brisk until the panic of 1893 caused the boom to disappear almost overnight. Thomas M. Clark, hearing about the vacant hotel, approached the owners and managed to buy the property to start Bay View College, which operated until it was destroyed by a hurricane in 1916.
In 1911 Willacy organized the Portland Development Company and negotiated with the Coleman-Fulton Pasture Company for land it had repossessed. This time the company voted $10,000 to improve Portland and adjacent land. Earlier that year they had authorized $28,000 to build a wharf with railroad facilities to take care of the company's expanding cotton business. Coleman-Fulton also piped water from a discovery well in Taft to Portland, which had no water supply of its own. Portland prospered until it was hit by hurricanes in 1916 and again in 1919. After the boom in 1910 the population grew to over 500, but it dropped by 1925 to 300, where it held steady until the 1940s, when it reached 1,200. The city was incorporated in 1949 with Daniel Moore as mayor. In 1952 the Reynolds Metals Company broke ground for an industrial complex on land purchased from the heirs of the Green estate. Afterward, growth was steady. An aldermanic government was approved by voters in 1962. During the early years Portland was a rail shipping center for vegetables, and for a short time it had wharf facilities that handled cotton. The irrigation of the Rio Grande valley curtailed the vegetable business, and the hurricanes put an end to dreams of a port. In the 1960s and 1970s Portland grew primarily as a bedroom community for Corpus Christi. In 1988 its population was estimated at 12,000. In 1990 Portland had a population of 12,224 and had grown into Nueces County. The population was 14,827 in 2000.