Things Can Take A While
Which brings us to the 27th Amendment, which only took a couple of centuries to be ratified.

Amendment Text

No law, varying the compensation for the services of the Senators and Representatives, shall take effect, until an election of Representatives shall have intervened.

Annotations

Regulating Congressional Pay

Referred to the state legislatures at the same time as those proposals that eventually became the Bill of Rights, the congressional pay amendment had long been assumed to be dead. This provision had its genesis, as did several others of the first amendments, in the petitions of the States ratifying the Constitution. It, however, was ratified by only six States (out of the eleven needed), and it was rejected by five States. Aside from the idiosyncratic action of the Ohio legislature in 1873, which ratified the proposal in protest of a controversial pay increase adopted by Congress, the pay limitation provision lay dormant until the 1980s. Then, an aide to a Texas legislator discovered the proposal and began a crusade that culminated some ten years later in its proclaimed ratification.

Now that the provision is apparently a part of the Constitution, it will likely play a minor role. What it commands was already statutorily prescribed, and, at most, it may have implications for automatic cost-of-living increases in pay for Members of Congress.