English: Partygoers commemorating the laying of the cornerstone at Abraham Lincoln Birthplace National Historical Park. The term 'cornerstone', also commonly called the 'foundation stone', is derived from the first stone set in the construction of a masonry foundation. This stone is important because every other stone will be set in reference to this very first stone. Thus, the cornerstone determines the position of the entire structure to come. Left to right: Major Archibald Butt, Rob't Collier, Pres. Roosevelt, Mrs. Roosevelt, Joe Cannon, Ethel Roosevelt Derby, Gov. Folk and Clarence Mackey.

• Keywords: nps historical; historical; president; presidential; roosevelt; theodore roosevelt; party; birthplace memorial; memorial; archibald butt; collier; mrs roosevelt; cannon; laying the cornerstone; cornerstone