Apart from India, US had a federal system whose features vary from India.
1. The powers of the Central and the State governments are equal.Both are sovereign in their respective fields.
2. The Us President is both the head of the State and the government and is a directly elected representative.
3. Separate Constitution exists for the centre and the states.
4. The Residuary powers are given to the states.
Though both the centre and the states have equal powers and states have separate constitutions, the importance of the constitution of USA is always acknowledged in certain matters. Both work collectively on matters infrastructure, borrowing money, collecting taxes etc.