Political conflicts among Tidewater, the Piedmont, Northern Virginia, and however many regions you wish to identify are a long part of the state's history. These differences led to a formal split and the creation of a new state, West Virginia, in 1863.
Some boundaries proposed for West Virginia during the Civil War extended much further to the east. The new state could have included all Virginia counties west of the Blue Ridge, and even all the counties along the Potomac River downstream to the Occoquan River. In the end, West Virginia included only three Shenandoah Valley Counties - and the southwestern Virginia counties within the Valley and Ridge province stayed with "old" Virginia, due to the influence of the railroad.

European settlers did not spread out through Virginia after 1607 like ripples from a rock thrown into a pond. Settlement did not expand equally away from a central point at Jamestown, with new farms and communities emerging a few miles in every direction every few years.
The English settled first in Tidewater Virginia, clearing the land near the rivers in the Chesapeake Bay watershed. Instead of a smooth, gradual spread outward from one central place, English settlement spread primarily to the north of the James and east of the Fall Line. South of the James, in the Albermarle-Pamlico Sound watershed, there was less demand for land in the first 150 years after Jamestown.
Why? South of the Appomattox River watershed, Virginia rivers do not empty into the Chesapeake Bay. Farm crops loaded on boats and shipped downstream end up in North Carolina. Farmers south of the Appomattox River could load boats to carry crops down the Blackwater, Nottoway, or Roanoke rivers - but those boats ended up in the Albemarle-Pamlico Sound, while most ships sailed to Chesapeake Bay ports.
By 1700, a gentry of 5% or so of the population (the "First Families of Virginia"or Cavaliers) took control of the politics and economy of the colony. The plantation owners shifted from importing indentured servants to importing slaves as the primary labor force for their tobacco plantations.
They built large manor houses on their Tidewater plantations - Berkeley, Carter's Grove, Mount Airy, Stratford Hall. Using their influence in the House of Burgesses and with the Governor, they obtained land grants and speculated in western lands - lands west of the Fall Line. The Lees and Carters competed in the upper Potomac watershed for control of the Fairfax land office and access to waterfront property downstream of Great Falls. Governor Spottswood led a real estate speculation expedition up the Rappahannock River valley in 1716. His "Knights of the Golden Horseshoe" crossed the Blue Ridge near where modern US Route 33 passes through Swift Run Gap. The "knights" celebrated their arrival with multiple toasts of wine, brandy, and claret on the banks of the Shenandoah River, in an evening party that is still memorable nearly 300 years later.
Modern real estate agents will recognize the expedition (and the party...) as a familiarization tour to spur land sales. The old saying about real estate values being determined by three things ("location, location, and location") applied in colonial times as well as today. Spottswood himself imported indentured servants to develop an iron plantation at Germanna, upstream from Fredericksburg, while defending his even-handedness in supporting development south of the James. Even today there appears at least the perception of colonial official bias towards settlement north of the James River, in the Chesapeake Bay watershed.
While the officials in Williamsburg processed requests for grants and occasionally an actual survey for a patent west of the mountains, a few of the gentry actually visited their land claims on the other side of the Blue Ridge. George Washington spent much of the 1750's in Shenandoah Valley and travelled south to Shawsville to inspect frontier forts. Patrick Henry travelled to visit his properties nearby in Christiansburg, a town named after his brother-in-law William Christian.
But most settlement west of the Blue Ridge came from a different direction, *not* from Tidewater Virginia. The House of Burgesses created new counties stretching to the crest of the Blue Ridge (such as Prince William) in the 1730's, but settlers did not spread westward in a steady flow. Instead, lands west of the Blue Ridge were settled by immigrants walking southwest from Philadelphia, before all the lands east of the mountains were fully occupied.
In an agricultural economy, the higher-quality limestone soils of the valley were one reason for bypassing the Blue Ridge. Even today, Virginia's two primary agricultural producers are Augusta and Rockingham counties. Recognizing the uneconomic value of farming in the mountains, Virginia purchased the hard-scrabble farms in the Blue Ridge 70 years ago and donated the land to the Federal government for Shenandoah National Park.
However, a more substantial reason for settling the Shenandoah Valley from the north rather than the east was cultural rather than physical.
The religious intolerance in Europe spurred many refugees to flee to the New World in the first half of the 1700's. Virginia had "established" the Anglican church as an official part of the government. Mandatory church levies (i. e., taxes collected by the sheriff) funded both social welfare and church operations, including the construction of the brick colonial churches still seen in Tidewater today (such as Bruton Parish church in Williamsburg and Pohick Church in Fairfax County).
West of the Blue Ridge, the Anglican and Tidewater English presence was far more limited. Immigrants coming south through Pennsylvania were predominantly Protestant - but not Anglican - refugees, people who fled the many conflicts among political states that have now been assembled into modern-day Germany. These Pennsylvania "Dutch" fled to William Penn's haven, the Quaker colony of Pennsylvania. They discovered the price of land was lower as they moved west, and substantially less as they crossed the Potomac River into the "empty" Shenandoah Valley in Virginia.
The valley was empty primarily because disease had dramatically reduced the population of the indigenous peoples, the Native Americans or "Indians" who had lived along the river for 10-12,000 years. [Shenandoah is an Indian word supposedly meaning Daughter of the Stars.] In the days when transportation was by one-horsepower wagon, the Blue Ridge was a significant physical barrier that divided the colony.
"East" Virginia was the Tidewater region, plus the Piedmont region where small planters produced tobacco for export. Those planters rolled hogsheads of tobacco eastward, downhill to the cities like Fredericksburg developing along the Fall Line, in order to ship their crop to Europe. Wagons that carried crops eastward to market returned home with nails, cloth, and other manufactured products. The mercantile system ensured that industries in England would have a market in the colonies, and the Fall Line cities became the "hinge" between the Piedmont and England.
But those cities were irrelevant to the immigrants west of the Blue Ridge, so long as roads through the mountain gaps were too poor for farm wagons. The immigrants who had come south from Philadelphia, migrating west to Lancaster and then following the limestone valleys south into Virginia, sent their farm products back north as well. Since the roads were poor (OK, really really poor), hauling tobacco to Philadelphia was a poor (OK, really really poor...) economic decision.
So the immigrants in the valley raised livestock, walking their herds to market in Baltimore and Philadelphia long before cattle drives of Texas longhorns captured Hollywood's imagination. If the movie moguls ever film a Virginia cattle drive, look for the herds of cattle from the South Branch of the Potomac River walking north, down the Shenandoah Valley.
Prior to the French and Indian War, the economic ties, religious sympathies, and family loyalties of the Shenandoah settlers were to the north, not towards Tidewater Virginia. However, after the Piedmont filled with settlers oriented to the Tidewater, a substantial number of "English" immigrants came into the valley across the Blue Ridge.
The French and Indian War triggered a decade of Tidewater commitment to the valley, from 1753-1763. George Washington lived in Winchester for several years as the commander of the Virginia forces, and the legislature and the governor committed substantial resources (though still far-from-enough) to fund forts and militia on the frontier from the Potomac to the New River. He was sensitized to the western attitudes and sought throughout his political career to use transportation improvements to link western loyalties to the primary American cities on the East Coast.
By the 1800's, roads crossed from Tidewater through the "wind gaps" in the Blue Ridge to the Valley. In the 1850's, railroads such as the Manassas Gap Railroad cemented the economic ties between the valley and the Fall Line cities.
But transportation improvements were never fairly allocated to the western counties of Virginia. After the Board of Public Works was created in 1816, the state financed 40-60% of the cost for turnpikes, plank roads, canals, and railroads. The legislature approved few projects west of the Allegheny Front, where the waters drained into the Ohio River.
Instead, the Tidewater-dominated General Assembly supported projects to enhance farm-to-market transportation leading to Petersburg, Richmond, and Fredericksburg. (Alexandria was part of the District of Columbia from 1800-1846, and the State of Virginia was reluctant to finance improvements to a non-Virginia city during those years.)
And the western counties were grossly under-represented in the General Assembly. The number of white males west of the Blue Ridge was greater than the equivalent population east of the mountains, when the state constitution was revised in the early 1850's. But the constitution was written so the western counties would never achieve control of the State Senate.
Tidewater planters were concerned that western voters would change the tax structure to finance "internal improvements." The Tidewater planters ensured property taxes on slaves remained low, while taxes on land were relatively high. The western residents had most of their investments in land while the eastern planters had invested in slaves. Instead of ensuring the tax burden was fair, the western residents were taxed more heavily - and the taxes were used to finance transportation improvements in the eastern portion of the state.
[Think there was ill will between the regions of Virginia before the Civil War? Northern Virginians benefitted when Whigs controlled the General Assembly, supporting internal improvements in the Potomac watershed such as the C&O canal. Democrats steered investments to the James River watershed when they controlled the political machinery. But westerners never got their fair share... no matter which party was in control before the Civil War.]
When the secession Convention finally voted to leave the Union in April 1861, the representatives of the western counties chose to meet separately and to "secede" from Virginia. This political decision was the final break, creating a fixed political boundary between two separate states after West Virginia was accepted into the Union. What had been a shifting frontier between Virginians who were oriented towards the Chesapeake Bay vs. the Mississippi drainage was locked into place.