Sidewalks are as old as Pompeii (2000 years or so)
Sidewalks are paid for by the land owners of the property they run across, whether they wish for the sidewalk to be constructed or not, Town of Minden v. Stewart et al. Southern Reporter, Vol. 77. November 26, 1917. pp. 118–121.
Research has found that riding bicycles on sidewalks is more dangerous than riding in the street.
Children who walk to school have been shown to have better concentration.
In the United States and Canada, the most common type of sidewalk consists of a poured concrete sidewalk, with horizontal strain-relief grooves faintly visible, examples of which from as early as the 1860s can be found in good repair in San Francisco, and stamped with the name of the contractor and date of installation.
When quantities of Portland cement were first imported to the United States in the 1880s, its principal use was in the construction of sidewalks. Its name is derived from its similarity to Portland stone which was quarried on the Isle of Portland in Dorset, England. It was named by Joseph Aspdin who obtained a patent for it in 1824.
Portland cement is one of the lowest-cost materials widely used over the last century. Concrete produced from Portland cement is one of the world's most versatile construction materials.
Portland cement had been imported into the United States, and in the 1870s, it was being produced near Kalamazoo, Michigan.
By the early 20th century, American-made Portland cement had displaced most of the imported Portland cement.
Sidewalks often were made in Ohio as a result of the urban postmasters insisting that before they would deliver mail for free in a city (in excess of 20,000 pre-1887, after 1887, the postal department opened the service up to areas with either populations exceeding 10,000, or postal revenues in excess of $10,000) the city had to put in sidewalks.
Before agreeing to establish free city delivery, postmasters could ask that the city's sidewalks be paved, the streets lit, the houses numbered, and that street names be placed at intersections.
Rural postmasters would later demand that roads be easy to travel and free of obstructions before service could begin.
The founding fathers of the United States believed the delivery of mail to be so essential to a healthy democracy that the establishment of Postal Offices and Post Roads was enshrined it in Article 1, Section 8 of the U.S. Constitution