A good example of checks and balances is the case of the Alaska Pipeline:

In 1968, oil was discovered in Prudhoe Bay, Alaska on the Arctic Ocean coastline. The problem was how to move the oil. The Arctic Ocean, being the best route, is frozen and impassable by oil tankers much of the year. A plan to move the oil by an 800 mile pipeline southward across Alaska to the southern port of Valdez was adopted.

Conflicts arose when the interests of Alaskan Natives, environmentalists, State government and National government conflicted. Various systems of checks and balances were put to the test in the forms of Federal vs. State, Courts vs. Executive, Congress vs. Courts, and Courts vs. Courts.

In the end and after costly delays the pipeline was built. The Alaskan Natives took title to the land and money for development, environmentalists succeeded in having public parks and wild reserves established, and the oil companies won the rights to drill and market oil. Checks and balances prevented any one power from restricting the rights of other groups.