An accompaniment to Mitchell's reference and distance map of the United States : containing an index of all the counties, districts, townships, towns, &c., in the Union, together with an index of the rivers, by which any county, district, township, &c., or river, may be found on the map, without difficulty : also, a General view of the United States, and the several states and territories, with an account of the actual and prospective internal improvements throughout the Union