Why is it that the US has been at war, in one form or other, since at least the Civil War.?

All part of the national pysche. They assume the rest of the world wants to be like them, whether they know it or not and act like bullies. 9/11 was really quite a shock for many ordinary Americans to find that many people around the world don't actually like them. After the disaster that was Vietnam, few lessons really seem to have been learned.

England and later the UK, has been at war for 654 of the 954 years since 1066. Their last peace time was in the 1930's and the longest period of peace was in the 1400's for a few decades.

It's not an unusual condition

Because, since the start of the Civil War, our society has been ruled by the Munitions manufacturers. They literally test their weapons on poor Americans. They think of us as cannon fodder. When Kennedy would not escalate the War in Vietnam they assassinated Kennedy and Johnson knew better than to defy his masters. The most loyal patriotic Americans volunteer to go into combat to defend the United States but their lives are counted as so cheap they're not issued dragon armour. Dragon armour is not for the poor boys, the 18 year old volunteers, and you have to pay for it yourself. They calculate these intentional blood sacrifices in statistics like 240,000. Hamburger Hill had that greenish glow you see on the battlefield after the Battle when the illoigor are feeding and the generals had that look, that horrible, ghastly look. Unless the People can ever nationalise the manufacture of Munitions and become a Nation of Munitions you shall never be free. Nationalise munitions and conquer the planet or remain forever Cannon Fodder and Blood Sacrifices sacerdotal to the Illoigor. It's your Manifest Destiny to rule the Planet and, by trying to act like a saccharine sweet ketchup attack, you are collapsing within yourselves. America didn't start out as a meek tiny little sissy and you cannot change now. Your trying to change into that will never fool the rest of the world. You have the momentum of karma and it won't let you. Stop and your Karma catches up to you. The bullies like Kim of North Korea don't buy it and you disappoint the people who are being killed by the Death Squads. The Little Guatemalan Girl had to walk with Jesus across Mexico and collapse dying at the Border because your president lacked the bolls to send rescue ships to liberate Guatamala. Kim threatens to nuke the West Coast and Trump goes to Korea to offer him his anus. Craven cowards dominated by Towel Heads. Vile submission. You are all belly up and pissing yourselves. The eagle's other claw holds arrows. Grow a damn pair.

It's not just the US. Europe and Asia have also been involved in many wars over the past few centuries. As long as there are armies and greed, there will be wars. Tyrants tend to covet what others have and use their armies to seize whatever they covet -- land, wealth, port cities or whatever.

It's in our blood, most of us are descended from Europeans.

Love of money is the root of all evil. Americans should think about the culture of open-source - sharing your interests with other free of charges. 

Conflict is, historically, the natural state of mankind. To single out the US is nonsense.

the 1849ers my friend. the gold rush prior to that there was limited gold in the world. in other words the world was dry.

then a huge lump was found and people been fighting over it ever since.

GREED!

The US was faced w/ challenges no other nation faced. They seem to be recent because of how young the country is comparatively. Why pick on the US? England has more yrs. of war than America's existence. The world has always been in a state of war someplace. I think there was one 100 yr. period of world peace called "Pax Romana".

The US tried mightily to stay out the 2 world wars but were dragged in. Both times it swayed the results ... you're welcome, Europe. You should be picking on Europe.

In the Bible, it seemed that everyone was at war all the time. Why?

We fought, many people, to gain our Freedoms and Rights.  As for overseas, 100%, of the time, country leaders or citizens have begged for our help so they can gain Freedoms and Rights.