In the spring of 1907, while at the
Department of Justice, Quackenbos continued to investigate cases of immigrant laborers held in
peonage across
Southern states. During this time, the
Italian ambassador to the United States, Baron Edmondo Des Planches, visited the
Mississippi Delta to investigate complaints of mistreatment of Italians who were laboring on cotton
plantations there. On June 4, 1907, he wrote to Secretary of State
Elihu Root requesting that Quackenbos investigate the conditions of Italian laborers in the Delta. While at Sunnyside Percy arranged for her notes to be stolen from her hotel room and then "recovered" by a close associate – sending the message to Quackenbos that she could not touch him. Percy used his personal friendship with then-President
Theodore Roosevelt to have Quackenbos removed from the investigation at Sunnyside. Ultimately though, her report was released, and the investigation resulted in a slowing of Italian laborers to the Mississippi Delta, as the Italian government began to warn immigrants away from settlement there. ==Criticism and resistance==