The beginning of railroads in this country date back to as early as the latter 18th century but the first noted commercial railroad which would become a common-carrier operation was the Granite Railway in Massachusetts dating to 1826. However, by most accounts railroading in this country kicked off in 1829 when the Delaware & Hudson Canal Company (which would later become the Delaware & Hudson Railway) tested a British-built steam locomotive called the Stourbridge Lion in August of that year. Soon after this successful test railroads began to pop up all along cities up and down the east coast. After further success of the steam locomotive as a reliable means of hauling goods and people by the end of the 1830s railroads were here to stay and would soon begin to sprawl westward.
With the creation of the Baltimore & Ohio Railroad on April 24, 1827 the common-carrier railroad (or a company whose intent and chartering was established to serve the public at large, handling both freight and passenger business) was born and so was an industry. The B&O began testing its first steam-powered locomotive in August of 1830 with the Tom Thumb, developed by Peter Cooper. A month later the South Carolina Canal & Railroad Company tested its own design the Best Friend of Charleston. This locomotive would also be the first American-built design to haul a revenue train when it carried a trainload of passengers on December 25, 1830.
Aside from the B&O (which connected Baltimore with Ellicott Mills and Washington, D.C.) and the South Carolina Railroad (which connected Charleston with Hamburg) other railroads being developed during the 1830s included the Mohawk & Hudson Railroad, which connected Albany to Schenectady on a 17-mile that opened in 1831 (the railroad used the famous Dewitt Clinton steam locomotive for power, one of the first ever tested in the U.S.); the Camden & Amboy opened in 1834 connecting New York harbor with Camden, New Jersey near Philadelphia; the New York & Erie Railroad of 1835 (predecessor to the Erie Railroad); and lines around Boston which connected the city with surrounding suburbs and also reached Providence, Rhode Island opening in 1835.
Also of note was Philadelphia's Main Line which was built during the 1830s as a combination canal and rail artery meant to connect western Pennsylvania with the Ohio River. Unfortunately it was much too cumbersome and couldn't even compete with the Erie Canal. While the first lines built in the 1830s were proving themselves as a reliable means of transportation not everyone was sold on the newfangled technology. Canal owners and the cities they served feared railroads would put them out of business while some of the public worried about the safety of pressurized steam boilers, collisions and other dangers associated with it. These fears were well justified but other more ridiculous assertions claimed railroads were a "device of the devil" and could cause a "concussion of the brain".
Despite these misgivings, the efficiency these early railroads allowed could not be argued. For instance, railroads could cut the distant it took between cities by steamboat in half. A good example is traveling between Cincinnati and St. Louis. By water this trip took 702 miles and three days but by railroad it took only 339 miles and 16 hours. Following the development of systems like the B&O, South Carolina Railroad and others new lines were rapidly built, so much so that by the 1840 mileage had reached almost 3,000 as compared to a few hundred in the early 1830s. Of course, new construction and development far outpaced safety and sound engineering practices, issues that would not be addressed for decades to come. During the 1840s even more railroads would be chartered, some which would become quite famous, and the decade would see improved technology in both equipment and infrastructure.
There are a lot of books out there covering various aspects of the development and history of railroads in our country. However, a good starter book is The Routledge Historical Atlas of the American Railroads by author John Stover. The book is small and general in scope but it gives a good introduction to railroad development through the 19th century, and the major railroads of the industry in the 20th century. If you're interested in perhaps purchasing this book please visit the link below which will take you to ordering information through Amazon.com.