It analyzes changing trends, profiles the dominant types of homicide in different periods of American history, and identifies some of the populations that have been differentially affected over time by homicide. Because no fully national databases exist for the entire century, the portrait of American homicide presented is a composite derived from national sources, when available, and a review of major studies in different periods. The review of homicide trends for most of the 20th century shows that the highest rates of homicide have occurred during the last two decades; whereas, the lowest rates occurred in the 1950's. Throughout this period, young black males have had much higher levels of victimization than other groups. In the most pronounced shift in trends, victims became younger toward the end of the century, with 15- to 24-year-olds becoming the group most at risk of homicide victimization. Family homicides, particularly spouse homicides, have proportionately decreased, especially in the last part of the century. At some specific times in specific locales, drug-related and/or robbery-related homicides increased as a percentage of the total. Gang-related homicides, although rare in the national picture, have tended to affect only certain cities. 5 figures, 16 notes, and 57 references