August 16 to 22, 1976, was designated as a stagnation period for a large part of the eastern United States by the Korshover technique, and Lyons and his associates judged August 16 to 28 to be a stagnation period. The effect of the 13 days of stagnation on five pollutants (total suspended particulates, carbon monoxide, sulfur dioxide, ozone and sulfates) and the association of various pollutants with restricted visibility are discussed in detail. Because long-range transport contributes to high concentrations of pollutants, trajectory analyses are included to indicate the approximate source-receptor relationships.