The residential segregation bill won the City Council’s approval of December 9, 1910…
Blacks simply were not allowed to live in white neighborhoods, and when it comes to mixed blocks, it was hardly the rule of law which reigned. Blacks who moved into mixed blocks were penalized when white politicians wanted to do so. The entire regime was extreme:
Baltimore’s innovation was the use of government legislation to achieve systematic, citywide race separation. “Nothing like it can be found in any statute book or ordinance record of this country,” the New York Times wrote. “It is unique in legislation, Federal, State, or municipal — an ordinance so far-reaching in the logical sequence that must result from its enforcement that it may be said to mark a new era in social legislation.” Baltimore thus became a national leader in residential segregation.
That is from Not in My Neighborhood: How Bigotry Shaped a Great American City, by Antero Pietila. Anyone interested in the roots of current problems in Baltimore should read this book