USA HISTORY

Detailed explanation-1: -By age 30, Carnegie had amassed business interests in iron works, steamers on the Great Lakes, railroads, and oil wells. He was subsequently involved in steel production, and built the Carnegie Steel Corporation into the largest steel manufacturing company in the world.

Detailed explanation-2: -Carnegie started work as a telegrapher, and by the 1860s had investments in railroads, railroad sleeping cars, bridges, and oil derricks. He accumulated further wealth as a bond salesman, raising money for American enterprise in Europe.

Detailed explanation-3: -With the U.S. railroad industry then entering a period of rapid growth, he expanded his railroad-related investments and founded such ventures as an iron bridge building company (Keystone Bridge Company) and a telegraph firm, often using his connections to win insider contracts.

Detailed explanation-4: -One of the captains of industry of 19th century America, Andrew Carnegie helped build the formidable American steel industry, a process that turned a poor young man into the richest man in the world. Carnegie was born in Dunfermline, Scotland, in 1835.