Boston's "high spine," of which 500 Boylston is an integral part, did not happen by accident. In 1961, when the old John Hancock Building was Boston's only skyscraper, a group of civic-minded architects envisioned a skyline of high-rise buildings that would define the city without encroaching on the historic neighborhoods of the Back Bay or the South End. Their vision has come to life in a row of distinctive skyscrapers that stretch from the waterfront past the Prudential Center, including the vaulted copper roofline of 500 Boylston Street, a building now woven into the fabric of the city, an important business address and an enclave of high-style shopping.