This is a 1930s era photograph depicting leveling the concrete foundation for the George Rogers Clark Memorial in Vincennes, Indiana, located along the Wabash River at the southern end of the state. President Franklin Delano Roosevelt later dedicated the completed memorial June 14, 1936.
If your memory of high school history class is a little rusty, George Rogers Clark defeated the British on a cold February day in 1779. According to the National Parks Service website for the memorial:
The British flag would not be raised above Fort Sackville Feb. 25, 1779. At 10 a.m., the garrison surrendered to American Col. George Rogers Clark. His American army, aided by French residents of the Illinois country, had marched through freezing floodwaters to gain this victory. The fort’s capture assured United States claims to the frontier, an area nearly as large as the original 13 states.
Although it depicts something a bit more mundane than capturing a fort, this photograph has us all enthralled with the small details--the engaged audience for the workmen, the process of leveling the concrete, and even the workman's coat hanging on a wooden post in the center of what will later become a beautiful monument. Go ahead and click on it to see it for yourself.