What can future civilizations learn from mistakes made during the Mesoamérica period and the civilizations that fell?

Which president created the cabinet? when?

It is 1902 i make 45,000 per year how much do i owe in federal income taxes

How did the cleveland massacre impact standard oil in 1872? standard oil hired all the laborers who were nearly killed during the cleveland massacre. standard oil became a monopoly in the cleveland oil market after the cleveland massacre. standard oil was bought out by other companies in the city after the cleveland massacre. standard oil closed down to avoid additional violence in the wake of the cleveland massacre.