The coal boom that began in the late nineteenth century and the need for tens of thousands of workers in remote mining areas led to the development of small company towns known as coal patches. In the early 1900s, Pennsylvania had more company towns than any other state, and the state's large number of municipalities today is a direct legacy of these coal towns. Coal patches were built and owned by a single company and were socially arranged, with owners, bosses, and foremen living in larger, better constructed detached houses on the main road near the mine entrance, while immigrants and unskilled workers lived in cheaper housing, most commonly semi-detached two-story wood-frame double houses. Miners paid rent directly to the company, usually at rates lower than private rentals, and the company store stood at the center of the patch, selling food, clothing, and mining supplies, often at higher prices but on credit. This system of rent and store credit kept workers tied to the company, while threats of eviction and withheld credit discouraged challenges to company authority and union activity. At the turn of the century, about 75 percent of patch residents were recent immigrants from southern and eastern Europe, and in larger towns they often grouped themselves by nationality in neighborhoods with informal names such as Pole Town, Swede Street, or Hunky Hollow. Crucible, founded in 1911 along the Monongahela River about 1.5 miles south of Rices Landing to house workers for the Crucible Coal Company, was a typical mining town. Its first miners' houses, built along Riverview Road, were semi-detached five-room homes with two rooms upstairs and three downstairs, and single four- or five-room houses were also built. These homes lacked electricity and indoor plumbing, relied on street hydrants for water, used outhouses behind the houses, and were heated by coal-burning fireplaces in every room except the kitchen. They had no insulation and were painted gray until white asbestos shingles were installed. By 1915, 40 single and 40 double houses had been built, while larger and better constructed single homes above the mine offices housed bosses, and additional homes for the company store manager and mine superintendent had electricity and indoor plumbing. The town also had a company store, community building, and school. The community building contained doctor's offices, a barber shop, a police station, and a movie theater on the main floor, with a bowling alley and pool hall in the basement and apartments for some security men on the second floor. The six-room elementary school, staffed by six teachers, held its first eighth-grade graduation in May 1919 with five graduates. By 1917, 140 more homes had been added. In the late 1920s, homes received electricity in the form of a ceiling light in each room, generated at the mine and subject to frequent brownouts and blackouts. In the 1930s, houses gained running water but still lacked bathrooms, and outhouses remained in use until after World War II. As coal demand increased, so did Crucible, and the population counted for Cumberland Township rose from 3,382 in 1920 to 7,187 in 1930 as Crucible and Nemacolin were included in the census. In 1927, an eight-room annex and auditorium were added to the elementary school, increasing the staff to 14 teachers for 525 students.