This week we celebrate our national Thanksgiving holiday. The holiday got its “official” start in 1863, when President Abraham Lincoln issued a proclamation inviting Americans to set aside the last Thursday in November “as a day of thanksgiving and praise to our beneficent Father who dwelleth in the heavens.” Thanksgiving’s traditional origin dates much earlier, to a harvest feast celebrated in 1621 by the recently-arrived Plymouth colonists and local natives. Some date it even earlier, to a service of praise and thanksgiving held in 1579 during English captain Martin Frobisher’s expedition to the New World…