Carnegie proved to be a model employee, wowing his boss with his skills and acumen. Scott, in turn, did much to nurture his protégé. In fact, Scott even initiated Carnegie's first investment when he tipped him off in 1856 about the upcoming sale of 10 shares in the Adams Express investment company. Carnegie persuaded his mother to mortgage the family home and snapped up the stock for $500, around $18,000 (£14k) in today's money.

With the railroad industry booming, the dividends began flowing in. In addition, in 1858, Scott ensured that a one-eighth interest in a company making sleeper cars was earmarked for Carnegie, who took out a bank loan of $1,250, or $47,000 (£36k) in today's money, to finance the acquisition. Reinvesting his returns, Carnegie also made several other lucrative investments around this time.

The poor Scottish boy who became the richest man in the world