Why were the Federalists in the Congress opposed to war against the British in 1812?

The Federalists opposed the War of 1812 because the policies of the opposing party that declared war, headed by Thomas Jefferson and later headed by James Madison, brought the Federalist stronghold of New England to the verge of destitution. Thomas Jefferson's embargo of American shipping, instead of protecting U. S. ships and sailors, caused massive unemployment, the closure of banks, and created a virtual standstill in commerce.