Article 1, Section 9, Clause 2
Document 6
Massachusetts Constitution of 1780, PT. 2, CH. 6, ART. 7
VII. The privilege and benefit of the writ of habeas corpus shall be enjoyed in this commonwealth, in the most free, easy, cheap, expeditious, and ample manner; and shall not be suspended by the legislature, except upon the most urgent and pressing occasions, and for a limited time, not exceeding twelve months.
The Founders' Constitution
Volume 3, Article 1, Section 9, Clause 2, Document 6
http://press-pubs.uchicago.edu/founders/documents/a1_9_2s6.html
The University of Chicago Press