This paper is able to put together a data base of 86 repeat sales transactions for office properties in lower and mid town Manhattan spanning the years from 1899 through 1999. Using this very limited data base, decade-interval changes in real property prices are estimated - with varying degrees of precision. Our conclusions are two. First, adjusting for inflation, commercial office property values are 30% lower in 1999 than they were in 1899. Secondly, within any decade values often rise and fall by 20-50% in real terms. With these results, the long term historic return to New York commercial property must be mostly be comprised of yield with capital gains limited to general inflation. Other historical studies consistent with this conclusion are reviewed. JEL Classifications: R51, N92.