There are approximately 233,000 miles of railroad track in the United States.
Source: http://www.co-ol.org/safetytips/safetytips.html
There was almost 3,00 miles of railroad tracks in 1840.
30,000 miles
35,000 miles of railroad.
From the end of the US Civil War in 1865, railroad construction boomed. By 1900 the US had 200,000 miles of railway track. This exceeded the total tracks of Europe.
There was almost 3,00 miles of railroad tracks in 1840.
There were 30,626 miles of railroad in 1860 according to Wikipedia.
3438 miles
225,000 Miles of track in the US in the year 1900 according to the video that popped up below this question by 5mins, IF I counted correctly. It was in increments of 15,000 miles and I only would have missed one. So there's the ballpark. According to the professor at DSC it is 193,000
The first US railroad was in Massachusetts, then Pennsylvania. New Jersey is one state that has retained some of the track from the early 1800's.
3438
By 1860 the US had almost 31,000 miles of railroad tracks.
Railroads generally avoid grades over 2%.