Mid-1700's
The predecessors to the National Road included buffalo trails, Native American foot paths, Washington's Road and Braddock's Road. The latter two were developed over a part of Nemacolin Trail, an Indian pathway, as part of the British campaigns to evict the French from the forks of the Ohio River. Visitors to the National Road can learn about this time period by visiting Fort Necessity National Battlefield. Fort Necessity is the site of the first battle of the French and Indian War (July 3, 1754) and the early military events that helped shape George Washington's character and abilities as a military leader. Not far from the fort, visitors can see Braddock's Grave and Jumonville Glen, site of the first conflict in the Fort Necessity campaign.

Late 1700's
Following the Revolutionary War (1783), and most particularly the victory of General "Mad" Anthony Wayne over the Indians at Fallen Timber in 1794, western migration increases dramatically as land starved citizens of a new republic begin settlement of the Ohio or Northwest Territory. The Appalachian Mountain chain provides a formidable barrier to trade and communication between the eastern seaboard and the western frontier. The 1791 imposition of a federal tax on whiskey, the primary commodity of trade for western farmers, leads to the Whiskey Rebellion (1791-1794), which threatens federal authority in the West. By the end of the 18th century, growing political and commercial concerns make the construction of a road over the mountains a necessity if the new republic is to survive and flourish.

1806
The Congress passes and President Thomas Jefferson signs enabling legislation to construct the nation's first multi-state, federally funded highway - the Cumberland Road (National Road). The legislation is nothing short of "revolutionary", in that it sets the precedent for all future, federal, public works projects.

1806-1808
Over 130 miles of wilderness is surveyed for the construction of the National Road, which is to have a right-of-way, 66 feet in width, and a maximum grade of five degrees (8.75%).

Construction of the National Road 1811 - 1830's
Road construction begins at Cumberland, Maryland. The base of the road is constructed of stone, with a gravel/sand surface. The road's surface measures 32 feet in width of which the center 20 feet is comprised of broken stones placed to a depth of 18 inches at the middle and 12 inches at the sides. The base's lower layer consists of broken stones passed through a seven inch ring. The upper layer is also broken stone passed through a three inch ring. The surface composition is gravel or sand compacted with a three ton roller.

1811-1818
Stone mile markers are erected on the south side of the National Road at 5 mile intervals.

1816
Uria Brown , upon traveling the new National Road writes, "The great Turnpike road is far superior to any of the Turnpike roads in Baltimore County for masterly workmanship, the bridges and culverts actually do credit to the executors to the same. " (These structures include the Casselman River Bridge, Youghiogheny River Bridge, Turkey's Nest Bridge, and the S-Bridges.)

1818-1820
Construction of the NATIONAL ROAD is completed to Wheeling, (West) Virginia. Congress appropriates funds to survey west of Wheeling with instructions that the road between that Ohio River port and St. Louis be as straight as possible.

1820's
The National Road is thriving and heavily traveled via horse, Conestoga wagons, and stage coach. , by farmers with livestock, prominent businessmen and politicians, and even presidents. Taverns, inns, and stagecoach lines are springing up all along the National Road. Towns connected with the National Road are prospering. Even before the construction of the Road is completed through Indiana and Illinois, Congress is forced to appropriate funds for repair to the road bed in the eastern most states. Macadamization of the surface begins in the late 1820's and continues into the early 1830's. Popular coinage of the National Road includes the U.S. large cent, U.S. half dollar, Spanish half reale and Spanish 2 reales.

1830's
The Federal Government transfers ownership of the National Road to the states through which it passes. The National Road becomes known as the National Pike, as some of the states erect toll houses to collect fees from those using the Pike. In order to create a revenue stream for maintenance purposes , the Commonwealth of Pennsylvania constructs toll houses along its 90-mile segment. Six toll houses (15-mile intervals) in all were built, two of which are still standing today: Petersburg Toll House - Gate #1, in Addison, Somerset County and Searights Toll House, in Fayette County. The toll houses were in operation from 1835 to the turn of the 20th century.

1835
The stone markers are replaced with cast iron obelisk mile markers. The iron markers are cast in Brownsville at the Snowden Foundry and in Connellsville by Major James Francis. The Connellsville-produced markers are located along the North side of the National Road between Cumberland, Maryland and Brownsville, Pennsylvania . The markers fabricated in Brownsville are located on the North side of the National Road that town and Wheeling, (West) Virginia . The new mile markers are placed at one mile intervals and total 133 between Cumberland and Wheeling. Each marks the distances to Cumberland and to Wheeling as well as to the closest town. Construction of the National Road continues through Ohio, Indiana and Illinois during the 1830's, 1840's, and even into the 1850's.

1835-1836
The United States Postmaster General Amos Kendall begins using the Pony Express on the National Road. Boys on horseback are used to deliver light mail in leather pouches. Each horse covers a distance of six miles average.

1840's
These are the peak years for travel along the National Road. Taverns and inns such as Tomlinson's, Searights, the White Swan, the Red Eagle, the Black Horse, Hill's and Washington's, enjoy a brisk business. Stage lines such as the National Road Stage Company, also referred to as the Stockton Line, the Good Intent Line, the People's Line, the June Bug Line, and the Oyster Line transport many famous persons along the Nation's "Main Street" including Presidents and future Presidents, Monroe, Jackson, Polk, Taylor, Harrison, Fillmore, Van Buren, Buchanan and Lincoln as well as notables such as LaFayette, Albert Gallatin, Henry Clay, Sam Houston, Daniel Webster, Davy Crockett, Chief Blackhawk, Jenny Lind, and P.T. Barnum.

Slack-water navigation of the Monongahela River begins year-round in 1844, with the construction of a series of locks and dams between Pittsburgh and Brownsville. The Baltimore & Ohio Railroad arrives in Cumberland from Baltimore, allowing passengers to transfer from train to coach to Brownsville and transfer there to steamboats for travel down to Pittsburgh and points beyond. Hundreds of thousands of passengers take advantage of this three-phase transportation systems to travel west.

1850's
A new form of transportation, the railroad, overshadows the National Road. In 1853 the first locomotive reaches the Ohio River. The prominence and prosperity of the National Road is overtaken by the "iron horse".

1860's
The dearth of traffic along the National Road is so severe that stage coach lines go out of business, inns and taverns are converted into private homes, commercial businesses disappear, and industrial activity declines. The National Road loses its "national" significance and becomes part of local road networks.

1870's
The states traversed by the National Road no longer want the responsibility of maintaining the obsolete and unprofitable roadway. Instead, responsibility is relegated to the counties, which, for the most part, provide little or no maintenance. The historic road is simply neglected or abandoned. Working inns, taverns and stage lines are few and far between. The once busy National Road is a transportation "has been".

1880's
A new, cheap, and reliable form of transportation is invented in the mid-1880's... the "safety" bicycle. Due to deplorable road conditions, cyclists begin the Good Roads Movement and the League of America Wheelmen. The movement gains the support of farmers and the railroads. The National Road is on the verge of being rediscovered.

Life along the National Road grew quiet for a time (1850's-1880's). All of that changed with the coming of the automobile and a new wave of touring in motorcars. Some of the first cars built in the United States are tested along the National Road, particularly at Mt. Summit. Tourists, driving the Road, stop at many waysides to eat, to shop, and to sleep. A new generation of travel and entertainment facilities appear on the landscape to meet their needs - gas stations, restaurants, motels and tourist cabins, drive-in restaurants and drive-in theaters.

1910's
The Post Office Appropriation Act of 1912 and the Rural Road Act of 1916 make available federal funding for rebuilding the National Road. World War I, an overburdened railroad system, and expanding numbers of motorists make a federally funded national highway system a top priority.

1920-1930's
The Federal Highway Act of 1921 provides federal aid for the construction of interstate highways. The National Road is realigned and incorporated as part of one of the first new interstate highways, U.S. Route 40.

1940's
The new National Road, U.S. Route 40, is the busiest it has been since its heyday during the 1840's. Instead of Conestoga wagons, there are tractor-trailer trucks, stages are replaced by buses and horses are retired to pasture in lieu of the automobile. Inns and taverns are updated as restaurants, motels and hotels. The hustle and bustle of travel has returned to the Road.

1950-Current
The Federal-Aid Highway Act of 1956 creates the limited-access interstate system. Interstate Highways 70 and 68 are constructed, and supercede U.S. Route 40 as the primary transportation routes through the region. U.S. Route 40 is bypassed and becomes a local, secondary, alternate, or, a scenic road. The National Road was designated a National Historic Civil Engineering Landmark in 1976 and a State Heritage Park in 1994. Along the 90 miles of road in Pennsylvania, 79 sites have been deemed eligible for listing on the National Register of Historic Places. Of those, many have already been nominated.