By 1860, the number of miles of railroad tracks throughout the united states had risen to
a.3,000.
b.30,000.
c.300,000.
d.3 million.

b.) 30,000

By 1860, the number of miles of railroad tracks throughout the U.S. had risen to roughly 30,000 miles, although it should be noted that this varied slightly depending on the exact year, since certain lines were taken down or moved.

this isn't a question and if you're going to list things be kind and use commas.

someone or something lol