I would start with a new 3/4" (copper) line in the basement, with a shutoff valve, and transition to poly before going into the crawlspace. (I wouldn't want that connection to be buried.)
After using sand mix cement to patch the hole in the wall, I'd cover the poly with sand for about a foot where it comes through the wall to help ensure it doesn't get crimped when the dirt in the back-filled trench is tamped and compacted.
I'm not familiar with foundation construction practices there, but are you sure your crawlspace wall extends 36" below the surface, or will you be into the footer?

Before you begin this project let us review your plan a bit.

Be very careful when selecting your "Hydrant Valve" because hydrants are made as both "Frost Proof" and "Freeze Proof" hydrants. In both instances the actual valving mechanism is at the bottom of the riser where the supply line attaches to the hydrant however, in a "Frost proof" hydrant when the valve is turned off there is still water in the riser up to the faucet spout and that water is subject to freezing just as if it were an ordinary riser and hose bib. A "Freeze Proof Hydrant" has the valving mechanism at the base of the riser but it also has a waste function which means that when the valve is turned off it will drain the water out of the riser, thus there is no potential for freezing. When installing a "Freeze Proof Hydrant" the hole for the hydrant valve should be about a foot deeper than the desired elevation of the valving mechanism and supply pipe. The hole is then backfilled with pea gravel up to the valve and supply pipe elevation, the supply connected to the hydrant, the continue to fill the hole with pea gravel for about another foot, then fill will dirt in the common fashion. In this manner when the hydrant valve is turned off the residual water in the standpipe can drain back into the pea gravel from where it will eventually leach into the surrounding soil.

No doubt you decided upon a 3/4" line because that is the size of the input on the valve you have in mind. Typically the hydrants used in residential applications are 1/2" and 3/4" inlets. A 1/2" inlet valve is rated at 5gal/min while a 3/4" valve is rated at 12gal/min. The length of your run from the source to the proposed hydrant location is 200' so in order to insure an adequate pressure at the hydrant we must also consider the "Friction Loss" of the pipe. In addition, as the volume of flow increases, the velocity of flow must increase proportionally but if the velocity of flow exceeds certain defined limits we start to see pipe wall erosion which leads to premature pipe failure. For that reason the pipe friction loss tables define not only the loss of pressure but also the velocity of flow and they define the acceptable limits for each size of pipe.

A 3/4" Polyethylene type SDR (standard dimension ratio) pipe is rated for a maximum flow of 8gal/min which would yield a velocity of 4.80feet/sec and a pressure loss of 5.84psi/100ft.

The 3/4" hydrant is rated at 12gpm and at 12gpm in a 3/4" pipe the velocity of flow is 7.21fps and the pressure loss is 12.37psi/100ft thus with a 200ft run the pressure loss would be 24.74psi.

If you were to then increase the size of the supply line from 3/4" to 1" the friction loss would now only be 3.82psi/100' x 2= 7.64psi and if you increase the supply to 1-1/4" pipe the friction loss would only be 1.01psi/100' x 2 = 2.02psi loss from the source to the hydrant.

In regards to how to et the pipe through the footer wall. The Plumbing Codes are very specific about how to pass a pipe through a masonry wall.

When passing a pipe through a masonry wall the pipe MUST BE sleeved. To make a sleeve you begin with a short piece of pipe 2 nominal trade sizes larger than the desired pipe and long enough to pass through the wall with 2" extending on each side. (The sleeve may be any type of pipe, I.E. Copper, black iron, galvanized iron, cast iron, ABS, PVC, vitreous clay, etc.) During new construction the sleeve could be inserted in a concrete form and cast into the wall, or we could have the mason set the sleeve while erecting a block, brick or stone wall. In a situation such as yours where we need to install the sleeve after the wall has been constructed we would first drill, bore or punch a suitable hole through the wall, then insert the sleeve and seal the sleeve to the wall by any suitable means. This may include cement mortar, tar or pitch or what is more commonly done today, expansion foam. Once the sleeve is set in place we can then pass the desired pipe through the sleeve and seal the space between the outer wall of the desired pipe and the inner wall of the sleeve with expansion foam to make it water tight and to prevent insects or vermin from coming through the sleeve.

Code requires that we must lay a pipe a minimum of 6" below the average frost depth. As was stated in the previous post when you get to your footer wall you may discover that your pipe depth is actually below the footer wall and at the footer depth. I would be very reluctant to make any holes in the footer which could ultimately weaken the footer. Instead, keep in mind that a residential footer is typically only 18" to 24" deep. I find it is much easier to just dig down a bit more and pass the pipe under the footer rather than go to all the bother of drilling the concrete and making a sleeve.

Thanks both for the excellent counsel.

Is a sleeve or other special treatment necessary to pass under the footings?

Some codes require it and some don't. In my opinion a sleeve is just too cheap and too easy not to do it.

One more point i forgot to mention. You will be required to install a Backflow preventer (check valve) at any convenient and readily accessible point before the line leaves the structure

(My apologies if this is a duplicate. I thought I asked this question but cannot find the answer)

Is it okay to place a Tee in the buried line for a future branch to a future hydrant? Is there a fitting designed to be plugged for future use? The reason is we may put another building up in the future and a hydrant would be good there.

It seems that burying and marking the Tee would be easier than splicing in a Tee at a future date.

Thank-you.

If you install a tee the line from the source to the tee location should be sized adequate for the flow rate of two hydrants.

You could install a tee then make a short stub-out, not exceeding 12" in length with a female thread adapter and plug or a male thread adapter with a cap on the end.