After Camp Grant was located at Rockford, the A. P. L. had much more work to do. While the buildings were going up, about 50,000 men passed through the employment bureau, from 7,000 to 10,000 being employed in the work. All classes of men were attracted to Rockford, and the local division was busy in keeping watch over them. Thirty-five I. W. W. members were taken from the camp laborers and handled in different ways—always with encouragement to go away and stay away. Two alien enemies were found among the laboring men at Rockford. They had come to America surreptitiously after the war began in Europe and had worked at various cantonments. They finally admitted they were German subjects, and were interned for the war. After the cantonment was completed and the troops began to arrive, the divisional activities of the A. P. L. centered largely in the detection of violations having to do with the morale of the troops. Five operatives were put to work on liquor cases, all working together under cover. Twenty-six men were sentenced for supplying soldiers with liquor, getting an average of ten months' imprisonment each.
The most notable case handled in Camp Grant, or in any other camp, was that which resulted in the court-martial of twenty-one negro soldiers. Louise S, a white woman visiting a white soldier at Camp Grant, was set upon and assaulted by fifteen to twenty-one negro soldiers on the night of May 19, the crime being committed on the reservation at Camp Grant. At nine o'clock that evening Major General Charles H. Martin, in command at Camp Grant, telephoned to the local chief to meet him in town. He said his officers had been unable to make any headway on the case, and asked that it be taken up by the Department of Justice. The League put men on the case, and in three days had twenty of the culprits in custody, ultimately securing confessions implicating all the others who were held. All of these men were tried by court-martial; fifteen were convicted and dealt with, five were let go, and one was declared insane. The assistance of the civilian authorities and auxiliaries to the military arm was so distinct in this case that General Martin wrote a frank letter of thanks, in which he said: "I am free to confess that until your entrance into the game, we had not progressed very far, and I wish to make it of record
