[1] The original purpose was to provide for secondary education, but as of the early 21st century, thirty of 151 existing union free school districts provide only elementary education.
16 "special act" union free districts serve only children resident in specific childcare institutions.
The board can shrink or grow over time within those limits, with the change made at an annual meeting of members of the constituency that elects the board.
A simple majority of the voters who attend the meeting can then confirm the change.
This article relating to education in the United States is a stub.