Answer:
Called for a constitutional amendment to empower the federal government to build roads and canals.
Explanation:
During President Madison second term the US had grown rapidly, the nation had gone bigger and transport and communication across the territory became a challenge.
New roads and canals were needed so the country could develop, Madison knew that. But he believed that the Congress did not have the authority to build them, so he defended that the Constitution should be amended so the federal government was authorized to build them.
Congress did not agree with that and did not amend the Constitution, instead, they passed the Bonus Bill, that was vetoed by Madison exactly because he believed that the federal government did not have the power to carry the execution of those powers.