What year was martin luther king day first observed as a federal holiday.

1986

Explanation:

In commemoration of Dr. King's birthday, the third Monday in January was declared a federal holiday in 1983 and observed for the first time in 1986

the protestant reformation's started in 1517, disturbing the religious and political order in europe´s catholic countries. the outcome was the european wars of religion prosecuted in europe in the 16th, 17th and part of the 18th century. nonetheless, uprisings, territorial disputes, and great power conflicts were also causes of the wars.