I've just finished Michael Holleran's 1998 book on the evolution of the preservation movement in Boston and America. It started a bit dry and academic - no surprise there, given the subject - but it went on to be quite informative. Featured are the early battles over the old Brattle Square and Old South churches, the Old State House, and the loss of the Hancock house on Beacon Hill. Over time, we see questions of motivation arise - what is worth saving, and why? A chapter on parks and open spaces leads on to a exploration of the skyline and building height limits, with an emphasis on Copley Square and Beacon Hill and the State House. The book ends with the institution of zoning regulations around the time of the First World War.
All in all, an interesting entry in the story of Boston and how the past was integrated into the modern city.
Boston's Changeful Times: Origins Of Preservation and Planning in America, by Michael Holleran.