In spite of the grid that existed from the time of Thompson's survey of the city in 1830, navigating Chicago was not simple. The house and street numbering system was inconsistent and became more so as Chicago annexed adjacent towns. In 1880 the City Council took steps toward addressing the problem with an ordinance that adjusted house numbers south of Twelfth Street (Roosevelt Road) to match the numbered streets on the south side, but the measure neglected the central and northern portions of the city. Large-scale annexations of 1889 complicated matters further throughout the city. In 1901, Edward P. Brennan proposed a solution, recommending State and Madison as the baseline for a city-wide street numbering system. In 1908, after years of debate, alterations, and improvements, the Chicago City Council adopted the plan, with implementation enforced beginning September 1, 1909. John P. Riley of the city's maps department was instrumental in hammering out the plan's final form. The initial legislation exempted the Loop, but after its initial success, the Council amended the ordinance in 1910 to include that area, with a compliance date of April 1, 1911. In the following years, Brennan campaigned tirelessly for the elimination of duplicate street names and to ensure that the names of broken-link streets would remain the same throughout the city. Hundreds of street name changes resulted, Brennan suggesting many of the names adopted. The current method for adopting honorary street names reflects the determination of city leaders to preserve this rational system. On Dec. 3, 1984, the City Council passed an Honorary Street Name Ordinance crafted by Charles O'Connor, head of the city's Bureau of Maps and Plats. Instead of changing a street's name to recognize a local hero, the city would create an honorary designation, posted on a special brown sign. The "real" address, however, for the purposes of mail delivery, police and fire departments, and the friend visiting from out of town, remained as part of the city's official grid-imposed street naming and numbering system.
Edward Brennan claimed never to have personally profited from his work on the reform of Chicago's addresses. His efforts were recognized in a resolution of the City Council on April 21, 1937. When Edward Brennan died in 1942, not only had the city been renumbered, but also at his urging the City Council had changed hundreds of street names. Brennan did not succeed in winning implementation for every aspect of his vision. For example, designations of Street, Avenue, and Road continued to be used randomly instead of being assigned to east-west, north-south, and diagonal streets respectively--but his overall plan still makes life easier for every Chicago resident and visitor.
Brennan began his renumbering campaign in the summer of 1901, as he recorded in a scrapbook of newspaper clippings.
The renumbering of Chicago's streets in 1909 and 1911 obviously required a great deal of preparation. Residents needing to notify correspondents of a new house number could find a variety of preprinted postcards in styles ranging from humorous to decorative to matter-of-fact. The August 21, 1909, Record-Herald headlined an article, "Postcard makers Reap Harvest on Change in City's House System."
Besides postcard makers, mapmakers also saw a dramatic rise in business as a result of the new system. This 1910 Rand McNally map shows that every eight blocks on the grid (starting from State Street and moving west) marks a major thoroughfare.
Brennan acted as chair of the Subcommittee on Street Numbers and Signs at the City Club, which actively campaigned for the elimination of duplicate street names and posting of clear signage. Among the items saved in Brennan's scrapbooks are a number of letters from companies ranging from Western Union and Marshall Field's department store to Riddiford Brothers Janitors' Supplies, supporting the plan to eliminate duplicate street names. After the second major renaming initiative in 1936, the proceedings of the Chicago City Council for April 21, 1937, proudly noted, "[T]here are now only 1363 street names in Chicago for 3624 miles of streets. . . . There are now fewer street names in Chicago than in any other city in the country of even one-half the area of Chicago."