The basic signs and symptoms of inflammation and wound healing have been appreciated for thousands of years. However, the specific cells involved and their roles in this complex environment are still being elucidated today. In 1926, the origin of the phagocytic mononuclear ameboid wandering cell (macrophage) had not been determined. One popular theory was that the cells were differentiated from the endothelial cells of the nearby blood vessels, whereas others believed that the cells came from the peripheral blood or resting wandering cells. The purpose of this article is to review the seminal article published by Lang regarding this topic nearly 75 years ago. In addition, this article will review what is now known with regard to the role of the macrophage and endothelial cells in the development of angiogenesis, which is arguably the most critical component of successful inflammatory process or wound healing.