The new developments in communication, transportation, and agriculture gave great impetus to industrial production. Other factors, however, also had considerable effect on the growth of industry. In 1807, while England and France were engaged in war, President Thomas Jefferson convinced Congress that all United States trade with foreign countries should be stopped. The president thought this move was necessary because both England and France were interfering with United States ships that traded with the other country. Congress agreed and acted. This act of Congress, the Embargo Act, meant that the United States could no longer buy goods manufactured in England. This act greatly increased the growth of factories in the United States. Items that were manufactured in England now had to be produced in the United States. Increased production introduced strong competition among American businesses, which in turn provided the incentive to search for better ways of production.

Progress does not always come about by desirable means. War is certainly one of the less desirable means. With all of its destruction and grief, war proves advantageous to those involved in certain industries. Demands on industry in time of war are great and constant. The production of weapons, ammunition, warships, and other military equipment keeps factories busy and profits high during war efforts. As soldiers leave their jobs to fight, many positions are left open. Not only does unemployment decrease, but many workers labor overtime to meet the production demands of the war.