Christopher Colles produced the first United States road maps in 1789. His atlas showed roads connecting a few cities, including Philadelphia in Pennsylvania, and was modeled after the English road guides of the 18th century. In 1796 Abraham Bradley made a large map of the United States showing the roads of the new nation (Pennsylvania detail) . This map, and its subsequent derivatives, became the official map of the US Post Office for planning mail deliveries; it is reproduced in Ristow and also Schwartz & Ehrenberg. In 1802 T. W. Jones and S. S. Moore produced a road guide similar to Colles called The Traveller's Directory, or A Pocket Companion, published by Mathew Carey, Philadelphia.

The old Lancaster Turnpike running from Philadelphia to Lancaster was the first long distance stone and gravel surface road in the country; see Hulbert, Rose, and this 1776 road map from the Library of Congress. It was built to provide cheap transportation from the breadbasket counties of Lancaster and York to Philadelphia. The Philadelphia and Lancaster Turnpike Road Company was granted a charter in 1792 and completed the road in 1795. Nine toll gates were constructed over the 62 mile distance. Pennsylvania also contains a portion of the only road built in the 19th century by the Federal government, the old National Road US 40, running from Cumberland into Ohio. It crosses the state in the southwest and had several toll gatehouses, one or two still standing today. The first iron bridge in the United States was completed in 1839 over Dunlap's Creek ( Brownsville) on the route of the National Road and replaced a succession of bridges at this location.The work was done as part of a reconstruction of the road by the Federal government prior to turning it over to the states for maintainance. The span is 80 feet and it still stands, a National Historic Engineering Landmark. And Pennsylvania built the first modern four lane highway in the United States, the Pennsylvania Turnpike. The first segment ran from west of Harrisburg to just east of Pittsburgh and opened for business in 1940.

Early 19th century maps typically indicated major roads, but with the coming of railroads mapmakers began showing rail lines (and canals) rather than roads. County atlases in the late 19th century would show roads on large scale county, township, and urban maps, and detailed road maps were published by bicycle clubs. In the early 20th century publishers again began to show main roads on atlas maps as car travel increased, and they began publishing road maps specifically for motorists. Some general American automobile road map history can be found in articles by Ristow (1946) and Yagoda, and in the book Hitting the Road by Yorke & Margolies. For a history of the Federal government involvement in funding and building roads, see USDOT in the references. A history of European road maps can be found at cartes routieres anciennes (old road maps).

Early automobile road maps had no route numbers. Major roads had historic names, i. e. National Road, Lincoln Highway, that appeared on road signs and maps. Early publishers of road maps created their own route numbers, and gave detailed driving instructions on how to get from place to place as route signs did not exist then. The state Highway Department used an internal system of route numbering from 1911 to 1925 that appeared on state produced maps but not on road signs or tourist maps. Trail or pole markings along the roads first appeared around 1917 and were an extension of the road name system. For example, the Lincoln Highway (US Route 30 today) was identified by a large blue L that could be seen on telephone poles or fence posts along the way. Old state route numbers first appear in 1925 and modern US route numbers in 1926 on a few major roads, i. e. US 30 and US 40. For more on early route numbering, see The Pennsylvania State Route Numbering System .

Oil company road maps have a special significance for Pennsylvania because the oil industry started near Titusville with Edwin Drake's oil well in 1859. Gulf, based in Pittsburgh, was the first oil company to hand out free road maps beginning in 1914; these maps carried route numbers that referred to detailed driving instructions published by the Automobile Blue Book Publishing Company. Most other oil companies began distributing maps in the 1920's, when route signs made using a simple map more feasible. General Drafting, Rand McNally, and H. M. Gousha dominated oil company road map publishing; other names were Mid-West, National Survey, Gallup, Diversified Map, R. R. Donnelly. Rand McNally began making maps for Gulf in 1922. General Drafting made maps almost exclusively for Standard Oil (Esso) beginning in 1923. The first Gousha oil company maps appeared in 1927.

Maps dated 1916 or earlier contain only publisher route numbers or road names. Maps dated 1917 to 1926 usually contain trail markings. Maps dated 1925-26 contain trail markings and/or old state route numbers. Maps dated 1926-28 may contain both old state and modern US route numbers on major roads. From 1928 on modern route numbers appear on all road maps. For a discussion and look at early road atlases, see Pennsylvania in Old Road Atlases.

Road maps are divided here into three categories. State Road Maps are those published by a state agency, usually the 'official' road map put out by the Highway Department. Oil Company Road Maps are those with an oil logo usually published by Rand McNally, H. M. Gousha, or General Drafting. General Road Maps are those not in the first two categories, though many also came from Rand McNally. This site may be searched using the search engine below.

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