ginjawarrior got it right. Something about having to drink water that is contaminated with industrial waste makes the people look to the government to regulate. I dunno.
The responsibility of the US government to regulate interstate commerce came in 1886 with the United States vs. Wabash case which responded to the robber barons of the railroad industry. What you might call "settled law" after more than 100 years on the books. Of course, this paved the way for the Interstate Commerce Act of 1887, Social Darwinism, The Interstate Commerce Commission, Sherman Anti-Trust Act,The National Labor Union, Federation of Labor, Knights of Labor, The Gilded Age, and others, not necessarily in that order. All of these things answering the question of "Whose responsibility is it to regulate business?"
Of course US v Wabash was based on a constitutional question. So really, the government has had the responsibility since 1776; Or depending on your school of thought, 1770; or 1781 when actual independence was won.