The fullback believes his side is making obvious improvements as the World Cup wears on, confident that the players are working well together.
Die Mannschaft secured a 1-0 win in Recife on Thursday through Thomas Muller's solitary strike, progressing through Group G as winners as a result.
Despite the relatively slight margin between themselves and the Americans, Lahm the victory represents a development on the 2-2 draw with Ghana and show that Germany are heading in the right direction.PHOTOS: USA vs. Germany | Beautiful people in Brazil
"We made big step forward," the 30-year-old told reporters. "We did better than against Ghana. We can be absolutely satisfied.
"That's what makes our team strong; that we are very defensive, that everyone defends. That is what's important in a tournament like this. I had the feeling that the team really works together - in the defense as well in the attack, and that's a good feeling."
Lahm also reserved special praise for his Bayern Munich teammates Bastian Schweinsteiger and Thomas Muller, singling out their contributions to the team.
"Thomas Muller is an excellent player," the DFB-Elf captain added. "He is very important for the team. He is a threat in front of goal, because he anticipates what happens in the box.
"Schweinsteiger has always been an important player for the national team. He is a big personality and therefore important for our game and our team.
"Of course, I notice the discussions about myself," he continued when asked about his own performance. "I don't live in a vacuum. It is important the team develops constantly."