Guests at the U-M birthday celebration dinner-dance mix and mingle as they arrive at the Union ballroom for the gala affair. At the speaker's table in the background, Mrs. Thomas Conlin (left) speaks with University President and Mrs. Harlan Hatcher, while Mr. Conlin, publicity chairman for the celebration, discusses some last-minute details with Daniel Shurz, chairman of the City Sesquicentennial Committee which sponsored the occasion. To their right Mayor and Mrs. Wendell E. Hulcher chat with Mrs. Gail Rector, whose husband was in charge of the program.