US constitution came into force on 1789 and is the first written constitution of the world. It also has statutes made by the congress, judicial decisions made by the American judiciary and orders passed by the president. American constitution is rigid as it needs a special procedure to amend. It is a federal constitution with each of the states having their own constitutions and a separate executive and judicial machinery like Governor and Supreme court and citizenship too.
Emphasis of the constitution is on separation of powers. President who is head of executive can veto bills of the Congress i.e. legislature. Supreme court can declare orders of president or congress as unconstitutional. President appoints judges of the Supreme court and congress decides the organization and appellate jurisdiction of the judiciary. Thus the system has adequate checks and balances.
Constitution is the Supreme Law of the land. No citizen can be deprived of rights granted by the constitution without due process of law.
President and his secretaries aren't members of the house so motions can't be used to control him. He is elected by an electoral college. The electoral college has members directly elected by the people. Its strength is 538. In each state the number of people is dependent on number of representatives in both houses. To win 270 candidates are needed and if no candidate gets a majority then lower house elects the President.
Qualifications:
He can be impeached for grave crimes. the lower house initiates the impeachment by majority vote. The senate tries the case here Chief justice of US acts as presiding officer. If senate passes it by 2/3rd majority then President is impeached.
He governs with the help of a cabinet which has people selected by him.
He isn't responsible to the congress and so can't dissolve the lower house. Controls present are:
Upper house or senate has 100 members with 2 from each state for a 6 year term. Its the most powerful house of the world. The lower house has 435 members with a two year term. American congress has special power that it can increase allocation given to an agency in the budget [not available in India]. Also the President has a Qualified veto i.e. if he vetoes a bill passed by the congress, the congress can overturn the veto by passing same bill with a higher majority [not in India].
American president unlike Indian president can hold a bill for maximum 10 days.
American civil service has a system of spoils and merit. The lower posts are filled by Office of Personnel Management but the higher policy making posts are outside the civil service laws and up to the discretion of the political executive to fill. No formal qualification criteria is there for the civil service. Civil servants can form associations or unions but can't strike. They have right to vote and can express views on political subjects [not allowed in India]. however other rights are restricted.
USA has position classification not rank classification like in India.