In the middle of the 19th century, Narva started to develop into a major industrial town. Ludwig Knoop established the Krenholm Manufacturing Company in 1857. The factory could use the cheap energy of the powerful Narva waterfalls, and at the end of the century became, with about 10,000 workers, one of the largest cotton mills in Europe and the world. In 1872, Krenholm Manufacturing became the site of the first strike in Estonia. At the end of the 19th century, Narva was the leading industrial town in Estonia – 41% of industrial workers in Estonia worked in Narva, compared to 33% in Tallinn. The first railway in Estonia, completed in 1870, connected Narva to Saint Petersburg and to Tallinn.