Overgrazing, overcropping, deforestation
When the price of oil drops this usually means that OPEC or a major state within OPEC like Saudi Arabia, or Venezuela has increased the supply of oil leading to a drop in price. This is the current policy of the Saudi Government which has led to a drastic decline in oil prices over the last 3 to 4 months.
In 1838, the city of Boston established the first American police force, followed by New York City in 1845, Albany, NY and Chicago in 1851, New Orleans and Cincinnati in 1853, Philadelphia in 1855, and Newark, NJ and Baltimore in 1857 (Harring 1983, Lundman 1980; Lynch 1984).