Locke is considered as Father or Liberalism. He focussed father of an individual rights of liberty and property life and a limited state. His thought is believed to form basis of American Political system.
Locke in his work Two Treatises of Government, promotes his Social Contract theory between civil society and state. His theory gives a limited power to state as he considers man to be rational. He gives inviolable right to life and property which cannot be taken by state. His rights further include dignity, liberty,
right against foreign domination etc.
He even gives the right to revolt to people if State is unable to fulfil its commitment. American political system includes a BILL OF RIGHTS provided inviolable rights to life, liberty and property except in severe circumstances.
The separation of power principle is also found in works of Locke. This is reflected in America with 3 organs of government - Judiciary, Executive and Legislature (Congress).
The founding fathers of American political system were inspired by Locke's work and incorporated the liberal principle in their system.