One reason the US railway system expanded so much in the latter years of the 19th century was the fact that there was allot of territories that needed railways. And, the railroad companies often with help from the Federal government had the funds to build them. By the 1880's the US contained one third of the world's railway mileage.
The development that caused large numbers of Jews to immigrate to the US in the 1880s was the rise of anti-Semitism and violence in Eastern Europe, particularly in the region known as the Pale of Settlement. Pogroms, which were organized attacks against Jewish communities, led to increased persecution and insecurity, prompting many Jews to seek safety and better opportunities in the US.
By the 1880's, the US railroad network contained nearly one third of the world's railroad mileage.
The division of the US into standard time zones was first done by the American Railway Association in 1883. This system was implemented to create uniformity in timekeeping for the growing railway network across the country.
The Baltimore and Ohio started construction in 1828. That is the first one that I know of. They started operating in 1830.
The North had a large complex railway system prior to the US Civil War and during it. The South being an agricultural economy relied on river transport to bring cotton and tobacco to their ports for exporting.
According to an 1880s census, most of the Osifs that came into the US were from Czechoslovakia.
There are several high speed railway line proposed in US. The most developed are the one in Florida and the one in California.
The establishment of a railway system in the US was least influenced by local agricultural needs, as many early railroads were primarily built to facilitate westward expansion and connect urban centers rather than to serve rural agricultural communities. While agriculture eventually benefited from railroads, the initial impetus for railway construction came more from industrial demands, resource transportation, and the desire for economic growth in burgeoning cities.
Some popular US railway books are as follows; Life along the line, The Railway Book, and there are several more. These books can be found in book stores or on the internet.
Question not clear. Do you mean 'Which parts of the USA were important in national development in the 1880s?' (You wrote 1808s, I assume you meant to write 1880s, or did you mean the whole of the 1800s?).
The US has the largest railway network of any country by far.
About Us - 2003 The Seattle-Tacoma Interurban Railway was released on: USA: 19 May 2006