A herdic cab is a type of horse-drawn carriage, used as an omnibus, invented by Peter Herdic of Williamsport, Lycoming County, Pennsylvania in 1881.

Take a look at this remarkable view down Pennsylvania Avenue in Washington, D.C. in about 1921. See the stunning photo and learn more about this historic view of the U.S Capitol.

This amazing old photograph of the intersection of 14th St. and Pennsylvania Ave., where the Willard Hotel sits, has some amazing details. Click to see them and be blown away!

Take a closer look at this detailed map of Georgetown from the Library of Congress. Click on the image for greater details and find out more about this historic map.

Check out this old photo of Georgetown's flooding and the Potomac River in 1918. Read more about it at The Georgetown Metropolitan.

Look back in time to 1855 and get a fascinating bird's-eye view of Georgetown, D.C. in this beautiful painting. Source: Library of Congress.

This lovely old image shows the site of the National Archives early in the construction process. It was taken on July 1st, 1932.

Discover the history of National Airport with a fascinating look back at the old terminal building in 1941. From its humble beginnings as Hoover Field to its critical role in World War II and subsequent expansion, learn about the changes that have shaped this important transportation hub in the heart of the nation's capital.

Can you help us in our investigation to identify where President Wilson's 1919 Pierce Arrow is parked? Take a look at the photo we've shared and see if you can figure it out. Happy sleuthing!

Take a look at the Federal Aviation Administration's headquarters on DC's Independence Ave. SW and compare it to what the block looked like in 1941 on the eve of World War II. See how the landscape has changed in this comparison.