Tell it to Israel.
tell it to China....
Israel’s wall is going to be 400 miles long when it is completed. Don’t see why the America that put a man on the moon can’t build one 5 times longer.
If one has ever been to Israel, looked at an aerial photo, of the land beside the Palestinian territory, you would see a wall in most areas as terrorists shoot through fences at Jews and/or non-Muslims.
The land there is certainly more rocky and rough than along our Southern Border.
Anyone claiming that "a wall can't be built," is saying "I don't want a wall to be built!"
Furthermore, anyone claiming "it would be way too expensive to build a fence," is admitting that money claimed that was set aside in 2006 and partial fences constructed under President Bush and Congress but never seriously intending on building anything, only tricking voters to think that our "leaders" planned on building any kind of barrier; and that person would also by lying about claiming that the expense of a wall would be cost prohibitive, and way less than we spend on illegal aliens (and their Anchor Babies) now, plus Earned Income Tax "Credits" to illegal aliens each and every year and on into the future so far as it exists!
Tell it to China.
Tell it to Hungary and the other European Third World Countries that are building them as fast as possible to keep the Islamic hordes out.
How long is the Israeli wall, how long is the Egypt/Gaza Wall, and how long would the US/Mexico wall have to be? Also, how long is the new Hungarian wall? The US wall will have to be close to 2,000 miles. Each of those miles will have to have a number of people guarding the wall to prevent breaking through, climbing over, tunneling under, etc. Also would be needed a staging facility with food, bathroom, office, bed, vehicles, etc. to maintain 3 shifts of personnel for each mile. How closely would the guards need to be placed, how close would the staging facilities need to be etc. Anyone want to estimate the maintenance cost of all that, plus the building of both the wall, the roads, the facilities, the training of the guard personnel, etc.?
So far as the Great Wall off China is concerned, there were actually several walls, built over periods of centuries, and they didn’t always keep the invaders out. They were more important as a paved road to travel quickly over rough terrain to quickly pass messages and get troops to where they might be needed for invasion in force. Here are hundreds of images of the walls with towers in high places, probably where troops and guards were stationed, and signals sent. Note that the crenellated walls along the road vary in places. Some have embrasures on both sides for archers, others only have them on one side, presumably facing the enemy. The mountains are impressive and you can see why roads were less popular.
At various times China has claimed different mileages of wall. The link below discusses potential claims and possible use for land disputes with Korea.
In all, when it came to major invasion, the Chinese wall did not keep the barbarians out. Unless they had large numbers of troops available to mass at an attack point, it was not that hard to get over the wall.