Environmental awareness has a longer history than we sometimes think:William Penn wanted to protect from development one settled acre out of five, and Benjamin Franklin was concerned with the ill-considered dumping of waste. But environmentalism as a movement really began in the second half of the twentieth century – some say with Rachel Carson’s Silent Spring (1962), a study of the impact of pesticides on the environment. In recent decades concerns about endangered species, air and water pollution, and global warming have become familiar subjects of debate. Where rivers and streams run – as they do here – making the water clean again is an important priority. Urban environmentalism is also center stage: what does it mean to make the city a green and livable resource, and how do we teach our children to value, protect, and nurture what we have? A healthy environment, after all, has implications that go well beyond the obvious: trees keep the city cool in summer, prevent run-off into the Anacostia and Potomac Rivers, control pollution, and even improve the air for asthma sufferers. Yet environmental charities typically receive only 3% of our philanthropic dollars. You may wish to change that!