The U.S. Army's much-heralded 4th Infantry Division -- which all but missed the campaign to oust Saddam -- rumbled into southern Iraq on Monday to reinforce the war effort.

About 500 vehicles in two convoys snaked their way along a sandy road, following advance units that had scouted the way under cover of darkness late Sunday up through Kuwait.

Hundreds of men, women and children lined the access road to the main highway inside Iraq, waving Iraqi dinars and running up to the vehicles whenever they would slow, offering the currency to American soldiers, presumably for dollars, though nobody stopped long enough to find out.

One little girl in a blue frock yelled out "Americans" and smiled and waved, while another with a white dress and black head scarf alternated between giving "thumbs up" signs and blowing kisses.

"Don't you just feel good about being here?" said Chief Warrant Officer II Tom Fisk, alternating between waving to the people and snapping photographs from the driver's side of a Humvee. "Did you see the happy people back there?" said Fisk, a 36-year-old Houston native with the 4th Battalion, 42nd Field Artillery Regiment.

With the last vestiges of Iraqi resistance crumbling in the northern city of Tikrit, it was not clear whether the 4th Infantry Division would see any action or take more of a stabilization role.

The 4th Infantry is considered the Army's most lethal heavy division, equipped with a sophisticated computer system linking all vehicles. The division boasts the latest tanks, Bradley fighting vehicles and Apache attack helicopters.

The division had initially been a key part of the war plan, to invade Iraq from the north through Turkey as the 3rd Infantry invaded from the south.

But the plan had to be abandoned after the Turkish parliament voted against letting the United States use Turkey as a staging area. Instead, the division's 14,000 pieces of equipment and 30,000 troops were shipped to Kuwait but arrived too late to be part of the initial attack.

As the convoy moved along the artillery-pocked highway Monday, burned-out tanks and abandoned infantry positions could be seen on either side of the road. Even on the main highway, children ran from their small mud-brick homes to the side of the road, waving and smiling. One young boy rode by on a brand new blue bicycle with a long shovel strapped to the back, giving the thumbs up as he pedaled alongside the convoy.

Even though the reception was welcoming, Maj. Steve Pitt, also with the 4th Battalion, 42nd Field Artillery Regiment, said it pays to remain wary and remember Iraq is still a combat zone.

"There's still a lot of danger ahead. You've got to stay focused -- one of those kids could run over and blow themselves up," said the 37-year-old native of Springfield, Va. "It's a great day for the division but we've got many tough days ahead."

Pitt was shocked to see the poor living conditions in Iraq after passing through affluent Kuwait.

"It's like when I was back in Germany for the fall of the Berlin Wall," he said. "You stepped into the East and it was like going back 40 years.