MOST Americans of middle age or older have heard of Jane Addams. Didn’t she have something to do with immigrants and social work? “She was a socialist, right?” queried an academic friend when I told her I was at long last writing my “Jane Addams book.” This vague sense of familiarity, absent any specific knowledge of who she was or what she did, is understandable. Not only do Americans study far less history now than they once did, but Jane Addams fell from public consciousness rather quickly following her death on May 21, 1935, at the age of 74. Statues of her never quite got off the ground. Planned memorials faltered.