There are many ways to collect subsets of the classic US commemorative series. I've discussed some in previous Quick Bits posts and have covered a good number in my topical Index posts (i.e., Coins with Ships, Coins with Hats, Coins with Eagles, etc.). For those with a particular interest in/fondness for early American history, a subset of the series that focuses on the colonies and early colonization attempts might be just the ticket!
Here's a quick look at such coins (arranged chronologically by history vs. coin release date):
1937 Roanoke Colony Memorial 350th Anniversary Half DollarThe oldest colony-related events commemorated in the classic US series are the 1587 colonization attempt on Roanoke Island in present-day North Carolina and the associated birth of Virginia Dare (the first child of English parents born in the New World). The 1937 Roanoke Colony Memorial Half Dollar was sponsored by the Roanoke Colony Memorial Association of Manteo, NC.
1920-21 Landing of the Pilgrims Tercentenary Half DollarThe 1920 commemorative half dollar that is commonly referred to as the "Pilgrim" among collectors was issued to commemorate the 300th anniversary of the landing of the Pilgrims in present-day Massachusetts - first in present-day Provincetown, then in Plimoth (Plymouth). The coin was sponsored by the Pilgrim Tercentenary Commission (Commonwealth of Massachusetts).
1924 Huguenot-Walloon Tercentenary Half DollarThe Huguenot-Walloon Half Dollar was struck to mark the tercentenary of the founding of New Netherland by Walloons (French and Belgium Huguenots) on behalf of the Dutch West India Company (DWIC). In 1624, the DWIC sent a group of settlers (mostly Walloons) to establish permanent settlements in the new Dutch territories. The commemorative half dollar was sponsored by the Huguenot-Walloon New Nederland Commission.
1934 Province of Maryland TercentenaryThe Maryland half dollar commemorates the 300th anniversary of the state's founding as a colony under a grant bestowed on Cecil Calvert (2nd Lord Baltimore) by King Charles I; settlers arrived in present-day Maryland in 1634. Cecil never traveled to Maryland, he sent his younger brother Leonard to oversee the colony. The coin was sponsored by the Maryland Tercentenary Commission.

For more "Colonization Commemoratives," check out:
Collecting Colonies - Part II For more of my topics on commemorative coins and medals, including more details on each of the coins mentioned here, see:
Commems Collection.