In 1908 the situation of 1906 was repeated. This time the Illinois operators refused to attend the Interstate conference on the ground that the Interstate agreement severely handicapped Illinois. As said before, ever since 1897 payment in Illinois has been upon the run-of-mine basis; whereas in all other States of the central competitive field the miners were paid for screened coal only. With the operators of each State having one vote in the joint conference, it can be understood why the handicap against Illinois continued. Theoretically, of course, the Illinois operators might have voted against the acceptance of any agreement which gave an advantage to other States; however, against this weighed the fact that the union was strongest in Illinois. The Illinois operators, hence, preferred to deal separately with the United Mine Workers. Accordingly, an Interstate agreement was drawn up, applying only to Indiana, Ohio, and Pennsylvania. In 1910, the Illinois operators again refused to enter the Interstate conference, but this time the United Mine Workers insisted upon a return to the Interstate agreement system of 1898. On April 1, 1910, operations were suspended throughout the central competitive field. By July agreements had been secured in every State save Illinois, the latter State holding out until September. This long struggle in Illinois was the first real test of strength between the operators and the miners since 1897. The miners' victory made it inevitable that the Illinois operators should eventually reenter the Interstate conference. In 1912, after repeated conferences, the net result was the restoration of the Interstate agreement as it existed before 1906. The special burden of which the Illinois operators had been complaining was not removed; yet they were compelled by the union to remain a party to the Interstate agreement. The union justified its special treatment of the operators in Illinois on the ground that the run-of-mine rates were 40 percent below the screened coal rates, thus compensating them amply for the "slack" for which they had to pay under this system. The Federal report on "Restriction of Output" of 1904 substantiated the union's contention. Ultimately, the United Mine Workers unquestionably hoped to establish the run-of-mine system throughout the central competitive field.