With these designs, Bethlehem Iron built the first plant to forge high-strength steel in America. The plant fabricated armor plates and guns for warships. Similar contracts gave the company, renamed the Bethlehem Steel Company, a consistent source of income, and Wharton made slow but steady profits. In 1901 he sold the company but continued to be the largest producer of pig iron in the country because of his extensive iron and coal mines and refining works. Over several decades, Wharton lobbied successfully in Washington, D.C. for tariff laws protecting U.S. manufacturing. He was a defender of large business and evolved into a staunch Republican. He successfully lobbied for the use of nickel in the U.S. coinage, but his lobbying for nickel tariffs was only partially successful, probably because he had a virtual monopoly on production in the U.S. In 1873 the world was in a very trying economic depression and many industrial firms went bankrupt. Wharton became widely known as a leader of the Industrial League of manufacturing concerns, and the main lobbyist and President of the American Iron and Steel Institute. He was a personal friend and consultant with several presidents including Grant, Hayes, and Harrison. Wharton entertained distinguished internationally known guests such as biologists Thomas Huxley and Joseph Leidy, astronomer Samuel Langley, scientist Lord Kelvin, Senators James Blaine and Justin Morrill, industrialist Andrew Carnegie, and metallurgist Alfred Krupp. Wharton successfully lobbied for a bill in the Pennsylvania General Assembly supporting Limited Partnerships to allow more participation of capital in enterprises with risk. Wharton was a scientist interested in the natural world, and wrote scientific papers on a variety of topics including astronomy and metallurgy, presenting several to the American Philosophical Society. In the winter of 1883–1884 there was a period of several months when sunsets were extraordinarily red worldwide. Some imagined that the red color was from dust dispersed in the atmosphere worldwide by the volcano Krakatoa which had recently erupted. Others imagined that the reddish hue might come from iron and steel furnaces because they were known to create a reddish-brown dust. Wharton was curious, and one morning when a light snow was falling, collected some from a field near his house, melted and evaporated it, studying the remaining particles under a microscope which he had on hand for metallurgy. The particles looked like "irregular, flattish, blobby" glass particles. He visited a ship that had come to port in Philadelphia, having sailed from Manila, a course that had taken it a few hundred miles from Krakatoa.