The name of this street was officially established as Sylvan Avenue Extension by a city ordinance in 1881. It was apparently viewed as an extension of the original Sylvan Avenue, which was renamed Swinburne Street in 1911. However, it seems to have been called simply Sylvan Avenue from the beginning: this is how it is labeled in the 1882 Hopkins atlas. After 1911, when there was no need to distinguish it from the "other" Sylvan Avenue, the use of the name "Sylvan Avenue Extension" ceased entirely.
- "An ordinance establishing the names of avenues, streets, lanes and alleys of the City of Pittsburgh." Pittsburgh city ordinance, 1881, no. 33. Passed Feb. 28, 1881; approved Mar. 4, 1881. Ordinance Book 5, p. 212. In Municipal Record: Minutes of the proceedings of the Select and Common Councils of the City of Pittsburgh, for the year 1880, pp. 213–234, Herald Printing Co., Pittsburgh, 1881 (Internet Archive pghmunicipalrecord1880). [view source] ordinance-1881-33
- "An ordinance changing the names of certain streets, avenues and alleys in the City of Pittsburgh." Pittsburgh city ordinance, 1911, no. 558. Passed Feb. 14, 1911; approved Feb. 16, 1911. Ordinance Book 22, p. 498. In Municipal Record: Minutes of the proceedings of the [Select and Common Councils] of the City of Pittsburgh for the years 1910–1911, appendix, pp. 322–323, Devine & Co., Pittsburgh, 1911 (Internet Archive Pghmunicipalrecord1910). Reprinted in the Pittsburgh Post, Mar. 10, 1911, p. 13 (Newspapers.com 86499788), and Mar. 11, p. 13 (Newspapers.com 86499822). [view source] ordinance-1911-558
- Atlas of the Cities Pittsburgh and Allegheny, plate 14. G. M. Hopkins & Co., Philadelphia, 1882. view source] hopkins-1882 ; 1882 layer at Pittsburgh Historic Maps ( ). [