The Quincy Railroad, for the transportation of granite from the quarries at Quincy to Neponset River, and the Mauch Chunk Railroad, from the coal-mines to the Lehigh River, in Pennsylvania, were the first attempts to introduce that mode of transportation in this country; and their construction and opening, in the years 1826 and 1827, are properly considered the commencement of the American railroad system. From this period until about the year 1848, the progress of the improvements thus begun was interrupted only by the financial revulsion which followed the events of 1836 and 1837. Up to 1848, it is stated that about 6000 miles had been finished. Since that date an addition of 5000 miles has been made to the completed roads, and, including the present year, new lines, comprising about 14,000 miles, have been undertaken, surveyed, and mostly placed under contract. The usefulness and comparative economy of railroads as channels of commerce and travel have become so evident that they have in some measure superseded canals, and are likely to detract seriously from the importance of navigable rivers for like purposes. In a new country like ours many items of expense which go to swell the cost of railroads in England and on the continent are avoided. Material is cheap, the right of way usually freely granted, and heavy land damages seldom interpose to retard the progress of an important work. It is difficult to arrive at a clear approximation to the average cost of railroad construction in the United States. Probably the first important work of this class undertaken and carried through in the Union was the cheapest, as it has proved one of the most profitable, ever built. This was the road from Charleston, in South Carolina, to Augusta, on the Savannah River. It was finished and opened for traffic in 1833. The entire expense of building the road and equipping it with engines and cars for passengers and freight was, at the date of its completion, only $6700 per mile; and all expenditures for repairs and improvements, during the eighteen years that the road has been in operation, have raised the aggregate cost of the whole work to only $1,336,615, or less than $10,000 per mile.