New inventions and improvements in transportation methods facilitated westward expansion during the Industrial Revolution. The introduction of steam power to river travel made upstream travel faster for passengers and goods, while canal systems made shipping even cheaper, connecting western farms to eastern cities. As transportation became more reliable and affordable, populations grew in western territories and new states were formed. While roads provided more access than rivers or canals, they were often poor quality and expensive. Rivers allowed cheaper and smoother travel downstream via flatboats and upstream via new steamboats, but flatboat travel was slow against the current. Canals linked western and eastern cities and economies but were very costly to construct.