Protesters demonstrating in the swimming pool of the Monson Motor Lodge in St. Augustine, Fla., scream as motel manager James Brock dumps muriatic acid into the water on June 18, 1964.

“The 1964 Monson Motor Lodge protest was part of a series of events during the civil rights movement in the United States which occurred on June 18, 1964 at the Monson Motor Lodge in St. Augustine, Florida. The campaign in June – July 1964 was led by Robert Hayling, Martin Luther King Jr., Ralph Abernathy, Andrew Young, Hosea Williams, C. T. Vivian, Fred Shuttlesworth, among others. St. Augustine was chosen to be the next battleground against racial segregation on account of it being both highly racist yet also relying heavily on the northern tourism dollar. Furthermore, the city was due to celebrate its 400th anniversary the following year, which…