Doesn't sound like a bog. Most of the water in a bog comes from rainfall. What you have could be a seep or a fen. Probably not very acidic. Anything other than horsetails growing?

Thank you for your answer.

The previous owner has tried to make this area part of his lawn so all that is back there is grass and the horsetail reeds that he has been trying to control with his mower.

I have a young son and a dog. I want to pervent tham from playing in this area so I thought a garden would be best. I love ferns, Jack-in the-pulpit, Astible, Snakeroot, Lily of the Valley, Burchberry, Kenilworth Ivy, Forget-me-nots, Chinese Lantern, Pitcher Plant, Toad Lily and Hostas. Along with the spungy soil it gets about half a days worth of sun... will these plants do well in these conditions?

Thank you again for your help.

Given that it is wet, there are certain ferns that would probably do well such as cinnamon, interrupted, sensitive, ostrich. Of the others I have experience with:

Jack-in the-pulpit - might be too wet. Arrow Arum might work as a substitute

Astilbe - I think these don't mind it pretty wet

Snakeroot - not sure. The one I know by this name is Black Cohosh (Cimicifuga racemosa), which I think of as being a more mesic species

Lily of the Valley - might be too wet

Bunchberry - If this is Cornus canadensis, it likes moist, acid soil. Doubt it would like it.

Forget-me-nots - Probably

Pitcher Plant - Likes it acidic. Doubt it would work

Hostas - Wouldn't have thought it would like wet roots but I saw one growing by a stream in a ravine once.

Some others that might do well include blue lobelia, cardinal flower, Oswego tea (Monarda didyma), marsh marigold, swamp azalea, gentians. That's all I can think of off the top of my head