The beginning of architectural acoustics as an engineering science began with Joseph Henry when he was requested by Congress to design a new lecture hall for the Smithsonian Institution in Washington. Henry's preliminary investigations led him to the discovery of what is now known as the “precedence effect,” setting limits on the permissible time lags in successive acoustic signals before echoing is evident. Henry's design of the lecture hall made skillful use of his discovery for the location and shape of wall and ceiling surfaces to produce much “early reflected sound” to enhance the direct impulses. The next great advance in architectural acoustics was made by Prof. Wallace C. Sabine of Harvard in his quantitative studies of reverberation, and in his masterful use of these discoveries in the acoustical designs for many notable buildings, especially Boston Symphony Hall—still considered one of the world's finest. After Sabine's untimely death in 1919 his work was extended and applied by many others in the next decade, notably, Dayton C. Miller, F. R. Watson, Paul E. Sabine, Carl Eyring, R. F. Norris, and Vern O. Knudsen. The early development and application of architectural acoustics as an exact science was primarily an achievement of the New World, and one of which we can be justly proud in the Bicentennial year.