“There goes the neighborhood!” refers to someone (or some business) entering the neighborhood and changing its character. The saying dates to at least 1964 and was a response to racially and culturally integrated neighborhoods. The line was popularized as a joke, as cited in February 1964:
 
“Mike Connolly relays a story about an Indian brave who glumly watched Christopher Columbus land and grumbled, ‘Well, there goes the neighborhood!’”
 
Comedian Norm Crosby used the same joke in his act by at least September 1964.
 
 
14 February 1964, Hamilton (OH) Journal—The Daily News, “Try and Stop Me” by Bennett Cerf, pg. 5, col. 3:
Mike Connolly relays a story about an Indian brave who glumly watched Christopher Columbus land and grumbled, “Well, there goes the neighborhood!”
 
22 September 1964, Boston (MA) Record American, “My Boston” by Harold Banks, pg. 23, col. 4:
When Columbus first set foot in the New World, Crosby (Comedian Norm Crosby—ed.) says, one Indian shrugged at the buck standing beside him and said resignedly, “Well, there goes the neighborhood.”
 
Google News Archive
3 April 1966, Eugene (OR) Register-Guard, pg. 12A, col. 6:
Art Buchwald
Well, There Goes The Neighborhood
WASHINGTON—When the flying saucers were sighted over Ann Arbor, Michigan, a few weeks ago, the first reaction from one of the residents was, “Dammit, there goes the neighborhood.”
     
OCLC WorldCat record
Dick Gregory’s Bible tales, with commentary
Author: Dick Gregory
Publisher: New York : Stein and Day, [1974]
Edition/Format: Book : English
Contents:
There goes the neighborhood (Luke 10:25-37)
 
Google Books
Literature of the American Indians:
Views and Interpretations:
A gathering of Indian memories, symbolic contexts, and literary criticism
Edited by Abraham Chapman
New York, NY: New American Library
1975
Pg. 154:
It is said that when Columbus landed, one Indian turned to another and said, “Well, there goes the neighborhood.”
 
OCLC WorldCat record
There Goes the Neighborhood
Author: Jane Holtz Kay
Edition/Format: Article : English
Publication: Change, v8 n11 (Dec., 1976): 54-55
Database: Arts & Sciences VI
 
OCLC WorldCat record
There goes the neighborhood
Author: Joe Walsh
Publisher: Los Angeles, Calif. : Asylum Records, 1981.
Edition/Format: Music LP : Rock music : English
 
OCLC WorldCat record
Whoops! there goes the neighborhood
Author: Blow Monkeys (Musical group)
Publisher: [New York, N.Y.?] : RCA, 1989.
Edition/Format: Music LP : English
 
The Internet Movie Database
Plot Summary for
There Goes the Neighborhood (1992)
Willis Embry, who is a psychologist in a jail, was left by his girl-friend. He has no time to be sad about it because an old man, who is very ill, tells him something about a robbery and the millions of dollars hidden somewhere. The old man asks Willis to find it and give a part of it to his relative, and he can keep the rest. In the next door some bad guy hears it and this causes the complications ...  Written by Kornel Osvart .(JavaScript must be enabled to view this email address)