You bet.
There's a reason why much top-notch leading paid SEO tools segment their traffic database by country.
Google pays attention to the geographic location of people's browsers and sends different rankings depending on where a person is coming from.
If you're looking for more US traffic, it's a good idea to make sure that your website is completely in American English.
Google can tell based on content spelling whether your traffic is more geared towards the UK or Commonwealth market than an American audience.
It also helps to localize your content towards certain parts of the US or America in general, depending on your niche parameters.