 The federal government approved the project and agreed to provide 80 percent of the funds for its construction in 1978, and construction on the extension began in March 1980.The extension was originally planned to open in 1982; however, its opening was delayed after a series of incidents including two strikes by workers on the line.The section of the extension from Jefferson Park to River Road, including Cumberland, opened on February 27, 1983; the CTA ran free shuttle trains between the new stations at River Road, and Harlem, the day before their opening so riders could "get acquainted" with the new line.