The correct answer is capitalism.
The increased pace of economic growth was most dependent on capitalism.
In the 1840s the U.S. economy grew more than it had in the previews 40 years. As the U.S. became more industrialized and farmers shifted to specialization the market revolution occurred and income rose. That is why the increased pace of economic growth was most dependent on capitalism.
Capitalism is an economic system. Private persons or private Company own the goods that are produced. In this system, the supply and demand regulate the prices of the market. The United States has followed the capitalism principals with success Its increased pace of economic growth has depended on this economic system.