moderated Re: Washington, DC Lafayette Park drawing
The Southern Railway Building is on the national historic register, and the park service has a web page about it: https://www.nps.gov/nr/feature/places/16000194.htm
According to that, the original building at the corner of 13th and Pennsylvania Ave. burned in 1916. It was replaced on site, but was demolished 10 years later for construction of the Federal Triangle. The "new" headquarters at 15th and K was built in 1928-29.