Campbell's cause for concern was real. Examination of the denominational preferences of sailed volunteers for the years 1910 to 1930 reveals that while in the earlier years the vast majority of the volunteers had sailed under appointment to mainline denominational boards, as the Movement progressed through the 1920s an increasing proportion of its volunteers were sailing under faith mission boards. This trend in the Student Volunteer Movement reflected a similar tendency in the general missionary movement. The Movement now found itself in danger of losing the support of the conservative core which was supplying an increasing proportion of its volunteers.