I grew up watching the NASL (North American Soccer League) that went belly up around 85 (coincidentally, my team was the last champs of that league their former coach became my college coach)... so yes, there has been pro soccer in the US, not to mention the MISL of the same era... now we have MLS... its not like soccer hasn't had many chances in this country... and they actually got national coverage as well as local market coverage on games back in the day... it just couldn't survive... as I said before, its a cultural thing, soccer just isn't a popular sport here... doesn't mean its a 'bad' sport and it certainly isn't from lack of exposure either... children have been taught soccer since they could walk in this country mostly cuz its one of the least expensive sports there is and literally anyone can participate...

I think your take on the relative importance of soccer in the US is dreadfully wrong... its not from lack of exposure or media or knowledge of it... baseball, basketball, and football are uniquely american sports that have only recently begun to have any appeal outside of the US... maybe if the european media and fans were not so ignorant of american football that sport would be bigger there, as would baseball... ugh