Freedom of Association: Country sources - Dominica

What is the oldest written source in this country that mentions this right?

Article 11 of the 1978 Constitution of the Commonwealth of Dominica guarantees freedom of association, including trade union membership.

References:

1978 Constitution of the Commonwealth of Dominica: "Chapter I: Protection of Fundamental Rights and Freedoms," Commonwealth of Dominica Constitution Order, 1978 (1978): 2919-2934: https://heinonline-org.proxygw.wrlc.org/HOL/Page?collection=cow&handle=hein.cow/zzdm0004&id=17&men_tab=srchresults