Are the berries very dark - smallish, and in an upright cluster *above* slender leaf whorls? And did you see white tiny blooms clustered above the leaves? If so, you may have an edible elderberry there.

They tend to sucker heavily underground - so look for signs of that around the base to help confirm. A google image seach, and one here on gardenweb & for net web pages may help confirm further.

I love to watch Cedar Waxwings in Elderberry trees in the fall. There's really nothing more peaceful or beautiful.

also the height of the plant - and other descriptive info would be important if possible. Bark color/texture soemtimes makes a difference. Elderberries can be a shrub or controlled to grow to standard tree. Berries are really dark- almost black.

Even if you aren't sure this is edible, you proabbly can use the dark berry as a stain/dye or ink. best to wear gloves when handling any plant parts that you are not sure about - as skin irritants and other poisons are very common in northern hardy plant country. I'd leave em for the birds until you are sure.