Today I went to the UWM Milwaukee library and looked at Wright's Street Guide Supplement for 1930. I thought it might help some of us if I shared the statement made in the supplement about how the street numbers were changed as of 1930. There were many street name changes that year, as well. Since I work on campus, I'd be happy to go back over to the library to look up old/new street/house numbers for people, if you just email me. Here's the quote from Wright's: New Numbering System The north and south base line division is N. First St., the Milwaukee River, S. First St., and S. Chase Ave., while the harbor entrance, Meomonee River, W. Canal St., and W. Stevenson St. constitute the east and west base line. All streets north and south of the east and west base line bear the prefix "North" or "South," respectively, while all streets running east or west of the north and south base line bear the prefix "East" or "West." All the houses and buildings are numbered on a basis of one for each 15 feet of property frontage, starting at the baseline with the number 100, and continuing with consecutive hundreds at each street intersection, wherever possible. Where only one number is available for any hosue or building, and such house has an upper portion, or the property a rear house, the same number is used, including the suffice "A," "B," "C," etc., as required.