B)Railroads - more cities could access railroads and increase trade. was built more in the 1800s.Canals was a short-lived era. [ Railroads beginning in the late 1830s and early 1840s were built because they were faster and more reliable than Canals which were often destroyed by washouts of the banks and floods destroyed many canals. The first transcontinental was completed in 1869, by 1900 there<span>were 15 transcontinental railroads. ]</span>
