Big Boy #4014 on its epic journey from San Antonio to Houston, Texas

Big Boy #4014, the world's largest operational steam locomotive, made its way across the United States in 2019 as part of Union Pacific's "Great Race Across the Southwest" in commemoration of the 150th anniversary of the completion of the 1,900-mile Transcontinental Railroad in Promontory Summit, Utah. This gallery gives a behind-the-scenes look at the train's vintage interior and exterior, as it made its historic trek from San Antonio to Houston, through the Texan heartland and enthusiastic crowds.