Looks like you are right: https://www.mainememory.net/sitebuilder/site/3283/page/5208/display?use_mmn=1 https://www.mainememory.net/sitebuilder/site/3283/page/5

Looks like you are right: https://www.mainememory.net/sitebuilder/site/3283/page/5208/display?use_mmn=1 https://www.mainememory.net/sitebuilder/site/3283/page/5208/... There was a 1874 court case where Granger claimed he owned the land by a deed granted the same year Massachusetts signed a treaty with the Passamaquoddy Tribe. The court decided for Granger. Under the treaty obligation, "it was Maine’s duty to compensate the Passamaquoddy for the value of the lost land, and to pay the Tribe's court costs and damages—neither of which happened." Maine couldn't simply change its constitution as the Articles of Separation requires "bars Maine from altering the Articles of Separation without the consent of Massachusetts and requires their inclusion in the Maine Constitution." To be clear, it appears there is no smoking gun which explicitly says this is the reason, but the people involve knew, or likely knew, about the case when developing the 1876 change. There is a 2022 paper on the topic titled “‘It May Be Questionable’: Granger v. Avery and the Redaction of Article X, Section 5 from the Maine Constitution“ at https://www.academia.edu/60751074/_It_May_Be_Questionable_Granger_v_Avery_and_the_Redaction_of_Article_X_Section_5_from_the_Maine_Constitution_ https://www.academia.edu/60751074/_It_May_Be_Questionable_Gr... which may have more.