Some tricky things you have to do- in google webmaster, bing website set your target USA.
After that your Research for your competitors, Develop the site which unlike your competitors.
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If your spending money for traffic then go for PPC with your targeted keyword.
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for organic International SEO make unique content, full seo friendly development, local usa search engine submission, domain must .com, or usa specified like co.uk, au

local business affiliate marketing.