150th anniversary of transcontinental railroad completion commemorated in U.S.

The historic Big Boy No. 4014 steam locomotive stops in West Chicago, Illinois, the United States, on July 29, 2019. The Big Boy No. 4014 steam locomotive spent three days in West Chicago during a tour to commemorate the 150th anniversary of the completion of the transcontinental railroad. (Photo by Joel Lerner/Xinhua)