I have been terminated from my job, officially without "cause", but the unoffical "reasons" are thin and I believe biased. I wonder if I have recours

I was employed at this company for 10 years, had only minor issues discussed at recent reviews (2012 and 2013). The issues were difficult relationship with clients (2), not technical work performance. Other reasons cited are that I don't "fit" with the future of the firm, they intend to take the firm concentration in another direction and my work experience doesn't "fit". I have been asking for years (4-5) to be provided opportunities at other projects, but have been told "there aren't that many opportunities, they are typically "so and so" types of projects; plus you are very good at juggling the 8-10 smaller projects, they are long term clients and they love working with you... " So I was stuck with those types of projects; pigeon holed, and now they have tarred and feathered me for being in the hole they put me in. I have also had medical issues in the past few years, and I believe my medical appointment schedule has played a part, although they haven't said so.