Concord grapes were very common in the northeast US. The grapes are round and a deep blue purple nearly black and have a rich flavor. They are typically used for jams/jelly, juice, pie and occasionally kosher wine. When I was a kid Welch's heavily advertised that they used concord grapes for their products. The lighter variety were possibly Catawba grapes. Catawba are common in the Finger Lake region and are used for jams and juice. There is also a red variety used to make New York Rosé wine.