<P> Around that time, he asked his cousin, George Lauder to join him in America from Scotland . Lauder was a leading mechanical engineer who had studied under Lord Kelvin . Lauder devised several new systems for the Carnegie Steel Company including the process for washing and coking dross from coal mines, which resulted in a significant increase in scale, profits, and enterprise value . </P> <P> Lauder would go on to lead the development of the use of steel in armor and armaments for the Carnegie Steel Company, spending significant time at the Krupp factory in Germany in 1886 before returning to build the massive armor plate mill at the Homestead Steel Works that would revolutionize warfare forever . </P> <P> By 1889, the U.S. output of steel exceeded that of Britain, and Andrew Carnegie owned a large part of it . By 1900, the profits of Carnegie Bros. & Company alone stood at $480,000,000 with $225,000,000 being Carnegie's share . Carnegie's empire grew to include the J. Edgar Thomson Steel Works (named for John Edgar Thomson, Carnegie's former boss and president of the Pennsylvania Railroad), Pittsburgh Bessemer Steel Works, the Lucy Furnaces, the Union Iron Mills, the Union Mill (Wilson, Walker & County), the Keystone Bridge Works, the Hartman Steel Works, the Frick Coke Company, and the Scotia ore mines . Carnegie, through Keystone, supplied the steel for and owned shares in the landmark Eads Bridge project across the Mississippi River in St. Louis, Missouri (completed 1874). This project was an important proof - of - concept for steel technology which marked the opening of a new steel market . </P> <P> The Homestead Strike was a violent labor dispute in 1892 that ended in a battle between strikers and private security guards . The dispute took place at Carnegie's Homestead Steel Works between the Amalgamated Association of Iron and Steel Workers and the Carnegie Steel Company . The final result was a major defeat for the union and a setback for efforts to unionize steelworkers . </P>

How did the growth of the steel industry affect other industries