Adam's included the following thoughts on the matter in his diary, which includes the quoted passage:
[Except from March 4th, 1835]
The greatest injury [the Speaker, John Bell] has done me was by appointing me Chairman of the committee on the bill from the Senate fixing the northern boundary line of the States of Ohio, Indiana and Illinios - a service which it was impossible for me honestly to perform with indisposing bitterly against me three whole States of the Union and twenty-nine members their Representatives in the house. This has accordingly been the result. Never in the course of my life have I known a controversy of which all the right was so clear on one side and all the power so overwhelmingly on the other; never a case where the temptation was so intense to take the strongest side, and the duty of taking the weakest so thankless. I cannot help suspecting Bell's motive for putting me upon it. Personally, to me it has been a great misfortune.
Memoirs of John Qunicy Adams, Vol IX (1876), pg 214