I overheard (read: eavesdropped) on two conversations on the subway this morning where the phrase “the back 40” was used. I’d never heard it before and now it’s nagging me.
2 questions:
What does this mean? I assume it’s a turn of phrase.
and
What’s the origin?
Cure that familiar nagging brain feeling for me.
It’s an old phrase from farming. The “back 40” (acres) was the field away from the “home field” (where the house and barn were located) and was generally considered not just remote, but less desirable.
The “south 40” is also used sometimes. Again, it’s an out-of-the-way part of a farmer’s field.
It doesn’t have to be an actual farmer’s field. People also use it as a little joke to refer to the part their (large) yard that is far away from the house. That part of the yard may be overgrown or not as cared for as the part closer to the house. A phrase related to this is “Time to go mow the back 40.”
the 40 in the phrase comes from “40 acres and a mule”. This was supposedly the grant that freed slaves would receive after the civil war. 40 Acres was a standard size farm 150 years ago.
I don’t think that the slave grant is particularly relevant here, except as another illustration that 40 acres was a standard farm size. If I recall correctly, 40 or 80 acres was also the standard size granted in the Oklahoma land rush. The reason why it’s a standard, incidentally, is that it’s a convenient dimension: A square a quarter mile on a side is exactly 40 acres.
It’s that plot of land that you give to crooning country singers in order to entice them to, “turn this rig around.”
My father, who grew up on a dairy farm, used “Back 40” all the time. And he said he was taught (well, not formally) that it referred to the farthest 40 acre section of the farm.
It was my father’s second most popular euphemism for using the toilet. He also used the word “going to the head” a lot, which is very unusual since he was never in the Navy. Presumably he picked that up from an older brother who joined the Merchant Marine.
I’ve heard it in daily conversation as a way of ending a conversation with someone as another way of saying “well, back to work I go” or “time to go plow the back 40”
It derives from the Public Land Survey System that was used to survey and organize the land in the US Midwest as the population expanded westward. The land was divided along latitude and longitude in 6x6-mile square “townships” divided in 1-sq-mi sections and in further subdivided in subunits thereof based on multiples of 40 acres. The way that counties managed this land and the public roads as history went along, often the road grid would be laid down so that the lands that would be granted would be developing starting from the fronting road, but some of those 40-acre units would end up “in the back”, away from the easy access to the road.
And if you drive in many rural areas (esp in the midwest and west), you’ll often see crossroads off the main highway at exactly 1 mile intervals. Sometimes the most exciting thing to do while driving thru those areas is to verify this… 
I had no idea this was a Navy phrase. I’ve used “hit the head” quite a lot and so have my friends. (I’m almost 30 from Chicago, if you need some data points.) Why is this particularly a Navy euphamism?
Because a ship’s toilet is called the “head” – officially. Sailors talk funny.
Politics played a big part as well:
Daaaaang. I wish there was something like that in effect today.
I’ve heard “lower forty,” I think in a song.
Think about it. Heat, cold, Indians, disease, hardship, crop failure, etc. Be careful what you wish for.
The Homestead Act was officially repealed only in 1976 (with an extension of ten years applied to certain loacations in Alaska). Unfortunately, you’ve missed that by 19 years. In 1977, Alaska initiated a Homesite Law that is patterned after the original Homestead Act. While I do not believe that the Homesite Law has expired or been repealed, a number of regulatory rulings have tended to eliminate its usefulness. However, to discover if there is any land still available under those provisions, you might check with the Alaska DNR.
Regarding the OP, note the provisions of the Homestead Act: it allowed one to claim 160 acres of land for the price of sweat equity. The “back 40” (as noted earlier) was the section of 40 acres (out of 160 acres) farthest from the house.
In days of sail the toilets were placed at the head end of the ship near the bowsprit so they would be cleaned by water splashing over the bow; see here.
Up on the north forty, I’m sure it was christmas day
When sir Rastus Bear taught children how to play