[Sacajaweau]

https://patch.com/maryland/annapolis/what-are-the-underage-drinking-laws-in-maryland

[Brown Deer]

What you posted are current laws. The legal age in Maryland was 18 until July 1, 1982, and those teenagers were grandfathered under the new law, and could still buy alcohol. What Kavanaugh said in his interview on Fox was, "The seniors were legal and had beer there."