Major Federal Agencies (civilian) dealing with environmental policies

from oldest to most recently established:

USDI - Department of Interior, 1849

USDA - Department of Agriculture, 1862

EPA - Environmental Protection Agency, 1970

DOE - Department of Energy, 1977

2009 Secretary and chief officer positions

USDI - Department of Interior, Ken Salazar (Colorado Senator)

USDA - Department of Agriculture, Tom Vilsak (Iowa Governor)

EPA - Environmental Protection Agency, Lisa P. Jackson (Agency attorney)

DOE - Department of Energy, Dr. Steven Chu (Nobel Prize winner)