What important transportation system made its debut in 1825?
a. the transcontinental railroad
b. the erie canal
c. the interstate highway
d. the new york subway

The best answer is B.

The Erie canal was opened on October 26 1825 by Governor Clinton. It had been first proposed in 1807 and constructed from 1817 to  1825. 

The Erie canal made an immense contribution to the wealth and importance of New York city, which later became the chief U.S port and fostered a population surge in western New York.

It served to increase trade throughout the nation by opening  eastern and overseas markets to mid-western farm products and it opened regions farther west to settlement. The Success of the Erie canal led to a proliferation of smaller canal routes in the region.