 A week later, in the largest mass arrest of rabbis in American history took place, while they were conducting a pray-in at the segregated Monson Motel.A well-known photograph taken in St. Augustine shows the manager of the Monson Motel pouring muriatic acid in the swimming pool while blacks and whites are swimming in it.The horrifying photograph was run on the front page of a Washington newspaper the day the Senate was to vote on passing the Civil Rights Act of 1964.