Wikipedia’s “Nicknames of New York City” states that New York has been called “The City with Everything,” but this nickname has been only infrequently used in recent years. “City With Everything” possibly borrows from American author E. B. White‘s nickname for New York—“Capital of Everything.”
 
The New York Convention and Visitors Bureau (behind the “Big Apple” campaign in the 1970s) promoted the fifth annual “New York Is a Summer Festival” in 1958 by calling New York “The City With Everything” in its tourist literature.
   
   
Wikipedia: Nicknames of New York City
New York City has been known by a variety of nicknames, both officially and unofficially, now and in the past. City nicknames can help in establishing a civic identity, helping outsiders recognize a community or attracting people to a community because of its nickname; promote civic pride; and build community unity. Nicknames and slogans that successfully create a new community “ideology or myth” are also believed to have economic value. Their economic value is difficult to measure, but there are anecdotal reports of cities that have achieved substantial economic benefits by “branding” themselves by adopting new slogans.
 
New York City is frequently shortened to simply “New York,” “NY,” or “NYC.” New York City is also known as “The City” in much of the United States. Other nicknames take the form of “The City with Everything” or “Hong Kong on the Hudson,” a reference in different cases to the city’s prominence or its immigrant groups.
 
New York (NY) Times
20 June 1958
The City With Everything
The fifth annual “New York Is a Summer Festival” season began yesterday, launched with the city’s blessing through Mayor Wagner and with the pomp and ceremony of promotional flourish. The festival, which frankly goes out to recruit the prospective vacation visitor, betrays the self-assurance of success now. Statistics have proved that it works, and to the benefit of almost everybody
       
Google Books
Printers’ Ink
Volume 265
1958
Pg. 71:
If you were in New York this summer you couldn’t help seeing ads, banners and brochures proclaiming that New York is “the city with everything.” The bally-hoo was part of the bureau’s “New York is a summer festival” campaign, now in its fifth year.
 
Google Books
Markets of America
Advertiser Magazine
Volume 24
1960
Pg. 112:
For these groups and others, New York is a proved “City with Everything.”
 
Google News Archive
8 October 1960, The Gazette (Montreal, Quebec), “Tourists’ Gotham,” pg. 25, col. 8:
And, says the New York Convention and Visitors Bureau, the sightseeing tours are effortless, educational introductions for youngsters and adults to the wonders of “The City with Everything.”
 
Google Books
Names and Sobriquets of U.S. Cities and States
By Joseph Nathan Kane and Gerard L. Alexander
Metuchen, NJ: Scarecrow Press
1965
Pg. 132 (New York City):
The City with Everything
 
Twitter
Dealery New York
‏@DealeryNYC
Escape the City With Everything From Canoeing to Wine Tasting http://bit.ly/rtxtC6 #nyc #deals
8:11 AM - 14 Jul 2011
 
Twitter
Mark Savel
‏@SavelSells
New York, New York… The City with EVERYTHING, except strong water pressure in the showers!
8:57 AM - 6 Sep 2012
     
The Huffington Post
Stephanie Be (Travel Blogger, Founder TravelBreak.net)
It’s OK to Cry: 11 Photos Celebrating New York—Sights You Won’t See in a Tour Book
Posted: 09/11/2014 6:03 am EDT Updated: 11/11/2014 5:59 am EST
(...)
A plethora of entertainment, art, and lifestyle awaits in “The City with Everything.”
 
Twitter
gogobot
‏@gogobot
A2. NYC has both the nickname “the city that never sleeps” and “the city with everything.” For good reason. http://www.gogobot.com/new-york-city  #TL_Chat
1:10 PM - 9 Dec 2014