The Rappahannock River is a river in eastern Virginia, in the United States, approximately 195 miles (314 km) in length. It traverses the entire northern part of the state, from the Blue Ridge Mountains in the west, across the Piedmont, to the Chesapeake Bay, south of the Potomac River.

An important river in American history, the Rappahannock was the site of early settlements in the Virginia Colony, and, later, was at the center of a major theatre of battle in the American Civil War. Due to its significance as an obstacle to north-south movements, it in effect functioned as the war's eastern-theatre boundary, between the "North" (the Union) and the "South" (the Confederate States of America).

The river drains an area of 2,848 square miles (7,380 km2), approximately 6% of Virginia. Much of the watershed is rural and forested, but it has experienced increased development in recent decades because of the southward expansion of the Washington, D.C. suburbs.

The name of the river comes from an Algonquian word, lappihanne (also recorded as toppehannock), meaning "river of quick, rising water" or "where the tide ebbs and flows," the name used by the local native population, the Rappahannock tribe.

Although there had been a few small hamlets along the lower Rappahannock during early colonial times, the settlement of the Rappahannock River valley began in earnest during the first years of the eighteenth century, at the urging of Governor Alexander Spotswood. The James River had been surveyed up to its fall line, the point where, geologically, continental bedrock of the Piedmont meets the sedimentary rocks and alluvial soils of the coastal plain. Spotswood encouraged settlement in a river valley other than that of the James. In 1714, he began soliciting immigrants from the Rhineland-Palatinate and Switzerland to homestead on lands he controlled near the confluence of the Rappahannock and the Rapidan. Known as the Germanna settlement(s), these villages were founded in order to exploit the iron ore deposits of the region.

The Battle of Rappahannock River was fought on the river during the War of 1812. Seventeen British boats filled with hundreds of marines and sailors captured four American privateers.

During the American Civil War, the river, with few convenient fords and fewer bridges, provided a barrier and defensive line behind which movements of troops could be accomplished with little fear of attack from the river-side flank. It was an especially difficult barrier for Union troops to overcome in their attempts to thrust into southern Virginia. Control of the river changed hands many times during the course of the war. Significant battles fought along the river include the Battle of Fredericksburg and the Battle of Rappahannock Station. The defensive line at the river was finally circumvented by Ulysses S. Grant in the Wilderness (or Overland) Campaign of 1864, ending in the ultimate Union victory.

en.wikipedia.org/wiki/Rappahannock_River