Premise: Now, we offer a simple way to make this clear, express limit make sense, and that is precisely the understanding we suggest that existed in 1790. The only precedents that existed in 1790 were precedents of setting a term, and then when parliament was asked in 1735, '37, and '39 to extend it, they rejected it, and as amicus historians said, they rejected it because, as a pamphleteer described it, that would be effectively a perpetual term.
Hypothesis: They are talking about the 20th century.