The Sumerian Amorite Wall was about 100 miles long and built between the Tigris and Euphrates Rivers. Of course there is a three-fold purpose to walls. KEEP ENEMIES OUT, DEFINE BORDERS, KEEP CITIZENS FROM LEAVING.
The Long Walls of Athens were built in 461 BC
The Great Wall of Gorgan (also known as the Red Snake) was built in the 5th century AD . It was 121 miles log from the Caspian Sea to the Elburz Mountains.
Hadrian's Wall was built in 122 AD. It was 73 miles long and went from Solway Firth to the Tyne River
The Great Wall of China was begun in the 3rd century B.C. and sections were added as late as the 14th and 17th centuries. It stretches thousands of miles.
Walls of Constantinople were built in the 5th century A.D.. It was about 14 miles long and include the Theodosian Walls
Berlin Wall was built in 1961 to separate East and West Berlin
Of course there are many more walls worldwide. Built for many reasons. Fences too. To keep enemies out, define borders and keep people from leaving. Some things never change.
So now we look forward to Trumpwall. It will go down in history too. If it is ever built. Odds?