From what i know, they went to find weapons and bombs of mass destruction. I've heard rumors that they went revenge for 9/11 as well. I don't know exactly and I don't think that the US government will be telling us anytime soon.
The US Army has suffered the most casualties in the Iraq and Afghanistan.
The US Army did.
The Iraq war caused many deaths. According to iCasualties, in 2012 one soldier was killed, in February. However, between 2003 and 2012, 4,487 soldiers were killed.
On 15 June 2014
The US is NOT at war with Iraq. The US was at war with North Vietnam.
The Army had units in Iraq first. US Army Special Forces were in Iraq before the war even began. As for the ground offensive, it was a simultaneous push - the border was crossed at several points simultaneously by both Army and Marine personnel, although I believe the first line unit fully across the border into Iraq was an Army unit. The first actual strike of the war, however, was dealt by the Air Force.
From 2003, and US troops are still in Iraq.
The US Army has suffered the most casualties in the Iraq and Afghanistan.
First, we should note the wording of the question. The US did not "restore" democracy in Iraq, since "restoration" requires that there was a previous state of democracy in Iraq. This is incorrect. There has never been democracy in Iraq at any point in history since Iraq was first settled over 5000 years ago. Iraq has consistently been ruled by absolute monarchies or in Caudillo-States or in one-party "republics" like Saddam's. The US created a new democracy in Iraq, changing the history of the country radically.The US role in creating democracy in Iraq was primarily the Iraq War, which was the invasion and overthrow of Saddam's Republic or Iraq. Afterwards, the US brought together leaders from different regions and clans of Iraqi society to write a Constitution that they could all finally agree on as well as facilitating the negotiations. The US also assisted monetarily, by financing the new government, and militarily, by training the nascent Iraqi Army. (Saddam's army had been disbanded and its members forbidden from re-enlisting.)
The first meeting of the US House of Representative was held on 1 April. George Washington becomes the first US President on 30 April. The US Army replaces the Continental Army on 29 September.
No nation, including the US is at war with the country of Iraq. Iraq is simply a nation that needs law, order, and stability restored to it. The US was bombing the nation of North Vietnam. The Army and Air Force of North Vietnam was fighting the US Air Force/US Navy in the air, and fighting the US Army/US Marine Corps on the ground. Two nations were at war with each other.
The first was over Iraq taking Kuwait. The second was an attempt by US to reduce Iraq's military power.
1940
There are currently over one hundred thousand US troops in Iraq. Beyond being a security issue, it would be prohibitive to list all service members in Iraq due to the sheer number of them.
USA
No. Once the sgt is granted leave it is all up to him at that point. He will still be on the army payroll.
The exact location of soldiers and units is considered confidential information and is not the sort of thing to share on a public message board. Watch the news and review news stories and you can figure out the general locations.