The Underline in Miami is weaving drab, underused areas into a 10-mile linear park designed for eco-friendly commuting and recreation. Parks, libraries, universities, museums, and concert halls have long relied on generous philanthropic underwriters to benefit a public seeking education, entertainment, and recreation. But in the past few years, wealthy donors have homed in on urban public parks and other “placemaking” projects with greater zeal—perhaps responding to cities struggling with shrinking parks, recreation, and infrastructure budgets, as well as growing inequality.
We found three such projects in the U.S., where land is being purchased or otherwise underwritten with philanthropic dollars. […]