Cobblestones have been used to pave roads since ancient times. For many centuries, cobblestones were an effective means of creating a durable road that would not wash away in harsh weather. Cobblestone roads passed out of general use in the 19th century but are retained in some areas for their quaintness or historical interest.
The first paved roads were built by the ancient Romans, who created a network of 50,000 miles of road to link all parts of the empire. All roads in the Roman Empire eventually terminated in the Forum in the city of Rome. Clivus Publicus was an ancient Roman street, which was paved with irregularly shaped cobblestones beginning in 238 B.C. Roman roads were usually made of layers of sand and stone, held together with a mixture of lime. The Roman roads were extremely sturdy, and some still exist.
Medieval roads were generally not well-maintained and were often simply tracks made by pack horses as they were driven across open countryside. Roman methods of road building were not kept up. However, the largest and most important roads were still sometimes paved with cobblestones, such as the road between Westminster and Temple Bar, which was paved under royal supervision in the 14th century. Later, 16th-century town governments passed laws requiring roads to be maintained; beginning in 1663, companies were allowed to build tollways.
Cobblestones were made smaller in the 19th century, because it was found that horses could step more easily when there were larger spaces between the stones. By 1900, the standard size was a 4-inch cobblestone. By this time, usage of cobblestones was already coming to an end. Throughout the 19th century, many roads had been paved with asphalt for a variety of reasons, ranging from more effective sewage drainage to the desire of governments to make it more difficult for rioters to build street barricades by pulling up paving stones. When cars began to replace horses for transportation, most remaining cobblestone roads were paved over.
Because cobblestones were standardised at a 4-inch size for the convenience of horses rather than people, it is not particularly easy or comfortable to walk on them. When cobblestone roads were in widespread use, they were not seen as being aesthetically appealing. However, because cobblestones are now seen as having quaintness, historical interest or Old World charm, some cities maintain a handful of cobblestone streets in tourist districts. For instance, the Old Port area in Portland, Maine, has several cobblestone streets.