Madison Neighborhoods, Inc

I live in the 53204 and have so for the last 10 yrs. I am so fed up with the slumlords in this area. They let gangbangers and everybody else just move in. Problem is I am a renter and not sure of all that I can do. Can anybody give me some advice on how to start cleaning up my block???? I am tired of the fights, spray painting and litter every where. I would like to find others in this area who like to help me figure out a solution to these problems.