English: This photograph shows Pioneer Square festively decorated and with crowds gathered about 1910. It is possible that this was a celebration in junction with the Alaska-Yukon-Pacific Exposition, held in Seattle in 1909 on a site that later became the University of Washington.

The brothers Clarence R. and Otto Langstaff were prolific amateur photographers in Seattle. Clarence (1880-1941) worked as a carpenter and also spent time at Mt. Rainier as a guide. Otto (1883-1969) worked for W.P. Fuller Company as a glazier and was a member of United Glass Union #188. Because most of their photos are not signed, it is often difficult to discern which brother was behind the camera.

• Subjects (LCTGM): Celebrations--Washington (State)--Seattle; Commercial streets--Washington (State)--Seattle
• People: Langstaff, Clarence, 1880-1941; Langstaff, Otto, 1883-1969