At this time of educational progress in the county, events occurred that changed the character of at least the southern half of the county, that established three new boroughs on the Ohio River, and that added more than 2,000 children to the school population in a period of five to seven years. The upper valley had a long history of light industry and water-powered manufacturing, but with the turn of the century, heavy industry moved into the county. The Ohio River, the railroads, the proximity to Pittsburgh, all combined in 1903 to bring the American Bridge Company to the bank of the Ohio about seventeen miles north of Pittsburgh, where it constructed an iron and steel plant near the village of Old Economy. The town that grew up around the plant took its name, Ambridge, from the company. Later, other manufacturing plants were built in the Ambridge area. Below the big bend of the river, near the Ohio border, in 1905, the Midland Steel Company built a plant on the farmlands that had existed there. In 1906, the borough of Midland was established. In the same year, 1906, the Jones and Laughlin Steel Corporation founded its Aliquippa Works - a huge plant that sprang up near the small town of Aliquippa and the village of Woodlawn down the river a bit and across from Ambridge.
In July 1912, the Report of the Superintendent of Public Instruction shows a large school population in Woodlawn and Ambridge and a somewhat smaller population in Midland. Beaver County's Superintendent David C. Locke emphasized the improvement in quality of instruction in local schools as shown in the increase of higher grade certificates. The number of professional certificates among the teachers of the county had increased over the preceding year. Holding professional certificates were 65 teachers.
The tabular statement of Beaver County for 1911-1912 shows 53 districts, including the new school districts of the industrial communities of Ambridge, Conway, Midland, and Woodlawn. Also added since 1900 were East Rochester, Homewood borough, Shippingport borough, and South Heights borough. The average school term was now 8.24 months. Female teachers numbered 373; male teachers, 77. The wage difference was even greater than in 1900. Average monthly salaries for men were $73.06, while women teachers averaged $50.49. The student population had grown considerably: 7,714 boys were enrolled and 7,635 girls. The average cost per pupil per month had risen to $2.17.
Finally, the districts of the county had to meet the hard conditions of educating rural children in the one-room schools of the townships or the two-room schools of the villages. It was in these schools that children received educations that permitted them to continue secondary education or fitted them for productive citizenship as adults. As late as 1945-1946, the county had 66 one-room (frame) schools and nine brick one-teacher schools in operation. The most primitive schools had disappeared in the nineteenth century - razed or sold or burned down. By the turn of the twentieth century, approximately 90 rural schools were closed in the county. Among the schools closing before the 1930's were the following: Knob in New Sewickley, 1910; Crab Hollow in Raccoon Township, 1911; Greene in Shippingport borough and the two-room Sharon School in Bridgewater in 1916; Roberts School in Hanover Township in 1919; Keifer and Doak schools in Hanover Township, Backbone in Independence Township, Lime Kiln and Groscost schools in South Beaver Township, all in 1920; Potter School in Potter Township in 1923; Frisco and North Star, both two-room schools in Franklin Township, closed in 1924; Marion Hill, a four-room school in Pulaski Township, and New England Hill School, also in Pulaski Township, in 1926; and Mount Nebo in Darlington Township in 1929. Here were 16 schools, each with its dedicated teachers, and hundreds of alumni. Alumni reunions are held yearly, and tributes to the skillful teachers still echo in oral and written remembrances. From 1930 to 1960, the rest of the one- and two-room schools closed their doors, replaced by larger buildings made possible through mergers and jointures - an educational pattern that became possible only after World War II.