Union Iron Works, located in San Francisco, California, on the southeast waterfront, was a central business within the large industrial zone of Potrero Point, for four decades at the end of the nineteenth and beginning of the twentieth centuries. History Peter Donohue, an Irish immigrant, founded Union Brass & Iron Works in the south of Market area of San Francisco in 1849. It was later run by his son, James Donohue. After years as the premiere producer of mining, railroad, agricultural and locomotive machinery in California, Union Iron Works, led by I. M. Scott, entered the ship building business and relocated to Potrero Point where its shipyards still exist, making the site on the north side of the Potrero the longest running privately owned shipyard in the United States. After Bethlehem Shipbuilding Corporation bought the works in 1905, the consolidated company came to include the Alameda Works Shipyard, located across the San Francisco Bay in Alameda and the Hunter's Point shipyard to the south. In 1885, the Union Iron Works launched the first steel-hulled ship on the west coast, , built with steel from the Pacific Rolling Mills. In 1886, UIW was awarded a $1,000,000 contract to build the cruiser for the United States Navy, which they completed in eighteen months. From the completion of Arago in 1884 to 1902, UIW built seventy-five marine vessels, including two of the most famous vessels of the Spanish–American War, and . An 1892 description of the yards stated that between 1200 and 1500 men were employed and the yearly gross revenue was between $2,000,000 and $4,000,000. By the turn of the century, the shipyard had expanded in area and employment had more than doubled to 3,500. These industrial facilities used five types of power, distributed throughout; electricity, compressed air, steam, hydraulic and coal or gas fire. Union Iron works built a number of ships for the United States Navy. These ships include USS Oregon laid down in 1891, and s and which were launched in 1902 and 1903, respectively. The latter two were subcontracted from the Holland Torpedo Boat Company, and were the first submarines built on the West Coast. In 1902, the Union Iron Works was absorbed into a combine called the United States Shipbuilding Company and was mired in three years of litigation. In 1905, the entire shipyard was purchased by Bethlehem Shipbuilding Corporation for one million dollars. Charles M. Schwab