1870
Carnegie meets Louise Whitfield.
A mutual friend introduces Carnegie to 21-year old Louise Whitfield, the daughter of a wealthy merchant. Carnegie continues to call on her family from time to time.

1872
Carnegie sees Bessemer's steel plants.
On a visit to England, Carnegie visits Henry Bessemer's steel plants. The Freedom Iron Company, which Carnegie formed in 1861, had been using Bessemer's process of making steel for several years. While in England, Carnegie realizes the commercial potential of steel and returns to America with plans to expand his steel business.

1873
Henry Clay Frick invests in coke.
In 1871, Frick organizes the Frick Coke Company with money borrowed from family and neighbors. By 1873, a financial panic hits the US and Frick borrows more money to buy out his partners and most of his competition. Four years later the price of coke had quadrupled and Frick had earned his first million.

1875
Carnegie opens his first steel plant.
Carnegie opens his first steel plant, the Edgar Thomson Works, in Braddock, Pennsylvania. The plant is named for the president of the Pennsylvania Railroad. Not surprisingly, Carnegie's first order is for 2000 steel rails for the Pennsylvania Railroad.