During the American Civil War there are two recorded cases of blood transfusion for the treatment of hemorrhage following leg amputation.

During World War I, the British attempted direct transfusion with poor results. O. H. Robertson (American) introduced preserved blood for transfusion in front line medicine using citrate solution as a preservative-anticoagulant. Only donors from blood group IV (Type O) were used, eliminating pretransfusion agglutination tests. Donors were selected from patients with minor wounds. History of venereal disease, malaria, or trench fever excluded the donor. The British adopted Robertson's technique and:

1. Established trained teams of corpsmen and nurses under the supervision of a program officer;
2. Distributed blood and coordinated planned distribution locations with line commanders at the battalion and regimental levels; and
3. Established specific indications for transfusion.

During the Spanish Civil War from August 1936 through January 1939, the Barcelona Blood Transfusion Service (BBTS) massively recruited donors significantly removed from the fighting front. The donor blood was forward and back typed and pooled by groups so that "very homologous blood is obtained." The BBTS followed up on each transfusion and kept records on each donor, each recipient, and each tube of blood.