The first artificial satellite was Sputnik 1, launched by the Soviet Union on October 4, 1957, and initiating the Soviet Sputnik program, with Sergei Korolev as chief designer. This in turn triggered the Space Race between the Soviet Union and the United States. Explorer 1 became the United States's first satellite on January 31, 1958. According to Wikipedia, by June 1961, three-and-a-half years after the launch of Sputnik 1, the Air Force used resources of the United States Space Surveillance Network to catalog 115 Earth-orbiting satellites.
This photo shows volunteers watching testing equipment that will help detect passing satellites at Edgewater Beach in Chicago.
Image is available for sale here: Satellite Watchers Original caption reads: Rodney Faxon shows new volunteer moon watcher Helen Gibbs how to use the moon watching aparatus. They are part of an organization of volunteers who watch the night skies for satellites as they traverse through space. October 5, 1958.