Priority had been given to shipping combat units, and service units made up only 21 percent of the theater's strength, which was insufficient. Nor were more units available in the United States; the mobilization program had also produced too few service units, and Somervell was forced to ship partly trained units in the hope that they could learn on the job. Perhaps 30 percent of the stores arrived with no markings indicating what they were, and 25 percent were merely marked by general type, such as medical or ordnance stores. Lee did not have enough personnel to sort, identify and catalog their contents. Soon vast quantities of stores and supplies could not be located.