The Jeffersonian Era 值,、2A America nearly doubled in size between 1800 and 1815 when they purchased the Louisiana Territory from France in 1803 for $15 million The Americans were defeating the Native American confederations in the northwest and south opening up space for white settlement The Supreme Court establishes Judicial Review which enabled the courts to review the constitutionality of federal laws and invalidates acts of Congress when they conflict with the ConstitutionThe Jeffersonian Era ◼ America nearly doubled in size between 1800 and 1815 when they purchased the Louisiana Territory from France in 1803 for $15 million. ◼ The Americans were defeating the Native American confederations in the northwest and south opening up space for white settlement. ◼ The Supreme Court establishes Judicial Review which enabled the courts to review the constitutionality of federal laws and invalidates acts of Congress when they conflict with the Constitution