Neither of my kids had any interest in sleep away camp. My husband starting teaching when my now senior was in 2nd grade; initially we had no money to send them. Then they grew to love “Camp Dad” and refused to even consider it! Looking back, I think what we gave up in monetary things was more than made up in summers exploring state parks and other cheap/free things with their dad - not many kids get to do that!
You lived in a city with fantastic mass transportation. Not all of us were so lucky.
My city didn’t have museums or notable places to go. We did have a baseball stadium, but it was way too far away to bike there as a kid! I got pretty bored during the summers and was very happy to return to school. Once I was old enough to work, that was my summer camp. I didn’t have a bad childhood by any means, but I admit that once I was old enough to move away from my home town, that’s exactly what I did.
@busdriver11 - I did that. Went to Blair Summer School for Journalism in Blairstown, NJ for five weeks between my junior and senior years in 1979. It was a very eye opening experience and I value it.
I know I have simple tastes but I didn’t realize how simple until I read this thread.
There are some amazing opportunities out there now, for sure. My older son went to Harvard for a summer school class, and chose a programming class that was very intense. It was so difficult for us to let him go to that, but it’s what he wanted to do…and now he’s a software engineer, so I guess it worked out.
“I don’t even understand what kids do at camp for the entire summer. What could be so amazing that instead of doing whatever you want in the summer (be it working, hanging out with your friends, enjoying the mountains or biking, floating on a raft in the lake), that you would spend the entire summer away from home? It sounds too much like school. Organized activities, crowds of kids (not all of whom you might like), not your own bed.”
Tennis, baseball, lacrosse, basketball, soccer, ropes, swimming, waterskiing, sailing, canoeing, hiking, plays, arts & crafts, Color War, Final Four, camp fires and that’s just off the top of my head. The girls also had equestrian and gymnastics. Since my kid left they’ve now added ice hockey for the boys. Plus, a weekly day trip which included water park/amusement park, hiking a High Peak, Cooperstown, etc., and the oldest do a three day trip to Montreal. There is also sports competitions with other camps.
All kids at my son’s camp have to go for all seven weeks so the kids really form a bond with their camp friends - and they all return every summer. Some of S’s closest friends still are his camp mates.
Most camps also don’t allow any electronics at all or phones. S’s camp didn’t even allow hair dryers!
No pool at my kid’s camp. Kids had to swim in freezing cold lake. Builds character. 
The only thing as a parent I hated was sewing the name tags on 100’s of things. There was no way to avoid as it was a uniform camp.
Camp is a big deal here in NE. Lots around to send the kids off. It really is just an offshoot of Boarding schools. You send your kids off to live away at boarding school when they are young and you send them to summer camps to keep them way. Kids learn independence and other valuable life skills. Our problem was always cash. Our kids did public school and stayed home summers. For them it was just not in the cards. 
When I was growing up, summer camp meant a few days to a week camping trip (like the kind that scouting and similar organizations organize), and certainly cost a lot less than $15,000.
I agree with @HRSMom and @MassDaD68 that extended camp is a Northeast/NY-area tradition. In part, because summers in NYC are just so tough. In part because there are so many Eastern/Central European Jews around NYC who brought with them the European tradition of leaving the city for the country for long parts of the summer. Of course, we’re talking about a fairly privileged group, since those camps never were terribly inexpensive. The less well-to-do kids had to make do with the Y.
Part of the reason camp became so ingrained as a way of life for people in Northeast urban centers was because of the fear of polio. So they were sent way in summer, then they sent their kids, and their kids sent their kids, etc., etc, etc.
I remember growing up hearing the commercials for the Fresh Air Fund to send underprivileged kids to upstate camps.
@NoVADad99, DH graduated from BxSci in 79. He went to IS 181, IIRC. His dad helped build Co-Op and they were original settlers there.
Just remembered I went to a yearbook editorial camp (paid by my HS) at UGA for a week the summer before senior in HS. Unbeknownst to me, Dh was there on a NSF summer project. Shortly after I met DH four years later, I was talking to a dining hall co-worker about my BF. I mentioned his name and that he was from the Bronx. Turns out she sat next to him on a Greyhound bus going from Athens, GA to Miami, where DH was heading to visit his grandmother. Small world!
A week after yearbook camp, I went to the Georgia Governors Honors Program. Six weeks away from home in my area of academic interest, fully funded by the state. That was a life-changing experience, to put it mildly. Opened up all sorts of new opportunities.
S1 went to HCSSiM (math program) the summer after sophomore year. It was a life-changer for him, too. Wasn’t nearly as expensive as many of the other options.
Maryland used to offer Gifted Summer Centers for 4th-7th graders with one-week sleepaway programs that were less than the cost of the local day camps. S2 LOVED these and spent time doing oyster and plant restoration on the Chesapeake, canoeing, historical reenactments and military strategy, etc. The definition of ‘gifted’ was nebulous, and meant if you were interested in the subject content, that was good enough for them. He would do two weeks of those in the summers and then went to the local archaeology day camp. He was later a counselor there, he learned CPR and got student service hours.
For the most part, like my parents did, we took our kids camping and sightseeing on vacations. Even got my Bronx boy hooked on it. All those years of Girl Scouts came in handy, too!
Weren’t they afraid they would get polio in a camp full of kids? The polio virus struck just as much in the fresh air as in the city.
You folks talk about the NE/NY area like it’s monolithic. (No wonder people are so dismissive of the Coasts). Season-long summer camp is only the norm among some demographics anywhere, even in the Northeast. I’m willing to bet many more kids don’t go than go–maybe not in your UMC neighborhoods, but in the rest of the world.
“Weren’t they afraid they would get polio in a camp full of kids? The polio virus struck just as much in the fresh air as in the city.”
I guess they weren’t. A quick google search brings up many accounts of popularity of sending kids out of the cities in summer which was time of year the virus spread quickly among large populations of people,
Here is one such account from the writer Chaim Potok.
.
"During the first two decades of my life, the thirties and forties, poliomyelitis was a frightful scourge made all the more horrifying in that most of the afflicted were children. Summertime the disease would run rampant through urban populations, striking randomly, at times paralyzing the legs and the respiratory system of its victims. Parents sought desperately to send their sons and daughters out of cities–to summer camp.
I grew up in New York, where the fear of that illness was so overwhelming that my father, a deeply religious man brought to ruin by the Great Depression, would send me to non-kosher Jewish overnight camps sponsored by local community centers, the only free camps available to us. Breathe the fresh air, he would say. Have a good time. He did not say what I read on his face and in his eyes: I am sending you Out of the city so you will be far away from this sickness that is crippling children."
I take it you and your father were first in line when the polio vaccine became available? Seems a lot less expensive than $15,000 summer camp.
^ Eh?
That was what Chaim Potok wrote about his experience.
When I went to sleep away camp (1961-69) it probably cost $1000.
It cost $50 for two weeks in 1971.
Well, I grew up in New England and kids just didn’t go away all summer. Maybe a week or two of scout or 4H camp. We were one of the places they would send Fresh Air Fund kids to. We had Fresh Air Fund kids stay with us for several summers. Summers were about swimming in lakes, riding our bikes to the beach or to the ice cream stand, wading in streams and catching pollywogs, fishing, building treehouses, catching fireflies, and not coming home until mom rang the bell for dinner. And hanging in a hammock or in the screened in porch and reading tons of books. Cookouts with other families, s’mores, watermelon seed spitting contests, pitching tents in the woods, pickup baseball games. Good stuff!
From my experience, the 7 week summer camps seemed to be common in certain WASP circles and among Jewish families. In more Catholic enclaves, definitely wasn’t a thing.
“Builds character” - that’s what my folks told me about working full time every summer since 13/14. I must have tons of character! 
It sure did build a work ethic, though.
By https://data.bls.gov/cgi-bin/cpicalc.pl?cost1=1000&year1=1965&year2=2017 , $1,000 in 1965 = $7,733.43 in 2017. (So about half as much as those $15,000 summer camps mentioned previously.)
Median family income in 1965 was $6,900 ($53,360.66 in 2017 adjusted by CPI), according to https://www2.census.gov/prod2/popscan/p60-049.pdf . (Not much different from today, though what you could buy then versus now was different.)
I honestly don’t know what it cost for my parents to send both my sister and me to camp. Maybe it was only $500 per kid for 8 weeks.
Camps, just like colleges, have gotten more expensive beyond adjusting for CPI and they are not hurting for campers as far as I can tell.
@doschicos, my S worked summers once he turned 16 (aged out of camp at 14) and worked summers, along with having an unpaid internship & breaks during college, plus had a job on campus starting 2nd semester his freshman year - so going to camp certainly didnt hurt his work ethic any.
I also never had to worry about him adjusting to being away from home or homesickness when he went off to college - since he was used to being away from home since he was six.