Q: How Long Did It Take to Lay The Cobblestones at Memphis?

A: Start-to-finish, the cobblestone paving took about 22 years. The
first paving project was 1859-1881; the final phase was 1879-1881.
The stones were shipped on riverboats to Memphis from about 7
locations with quarries that had stone best suited for the purpose.
These carefully selected stones have lasted 150 years in good
condition.

So, what is the problem with the stones? No problem at all with the stones themselves. Problem is a lack of maintenance and dredging too close to the base of the landing. Those are fixable. Sand and soil, not mortar hold them in place, creating a permeable and sustainable riverfront landing.