Several days ago, I was terminated from my job at a financial firm, which I had predicted ten months ago when I was essentially demoted and replaced by someone upon revealing to my bosses that I had breast cancer.

Here are the facts, and I just want to know if I either have a legal case or can at the very least receive Unemployment:

1. My bonus last year was extremely high and I met all of my performance review goals--I am an analyst, and my performance was well above the benchmark last year. I was told I was doing wonderfully. The praise, encouragement, etc, literally stopped immediately after I went in for surgery for cancer and treatment that followed, which took me out of work for three weeks, total.
2. Upon my admission that I had cancer, my employer began interviewing for what I thought was going to be an assistant for me, but turned out to be my replacement. 2 months before this person started, my job title and responsibilities were changed to be something incredibly ambiguous and difficult to measure performance on (unlike an investor, whose numbers speak for themselves), and I was told that this was being done because I had requested it (which is completely untrue, and I verbally protested my job changes to no avail). My boss then began yelling at me for everything, and made a point of documenting criticisms over email. I would say that about 80% of the things she was upset about were completely made up, and the rest were exaggerated, and whenever I would defend myself, she would tell me that I was too defensive and had a terrible attitude.
3. This is not related, but important I think because it could be a case in itself. 2 years ago, a managing director at the firm told me while we were having dinner that "you {referring to myself and another 4 younger women there who were about to get married or just married} must be frustrated, because we aren't going to promote people who are about to get married and have kids into higher up positions. This person is a woman (believe it or not!) who did exactly that when she had kids--took 15 years off to raise them. I reported this to our CEO, because I was concerned that I would be treated differently on the assumption that I am about to pop out kids, and the CEO got very defensive but never brought it up again (if only I'd reported it to HR!). I did tell a confidant who I worked with, but he would probably not defend me if it were me or his job.
4. I am being told that I was fired for my negative attitude (which is untrue--I actually was on excellent terms with all my colleagues and the only negative feedback I ever received was from my boss, and all of it was post-cancer), my laziness (I worked at least from 8-7 on an average day, was very productive, and can prove that), and my inability to "shift with the changing business needs that the investment environment has provided".

I am no dummy. I knew I was being set up to be fired a long time ago, but I just didn't think anyone would be that cruel! I should also add that the firm isn't doing well financially but has (over)hired a ton of new people recently, which is good cause in their eyes, I'd guess, to try to flush out those who they feel are eating up costs.

I would love to hear your ideas on where I can go from here.

>>I just want to know if I either have a legal case or can at the very least receive Unemployment<<

I don't see where you have anything to lose by filing for unemployment. Go for it!

You have a "case", but how good a case and how likely you are to win anything would best be determined by an experienced employment law attorney who has access to all the facts of the case, and not just the summary you have posted here. There are several red flags raised by what you've posted; of course we've only heard your side of it and your former er might paint a very different picture. But based solely on what you've reported, the timing of several things looks highly suspicious and looks like it could be discrimination/retaliation, and thus you seem to be painting what is called a prima fascie case (it looks like it one the surface). However, to put it in the vernacular, just because you give a picture that looks like a duck doesn't mean you can go into court and prove it has a bill, wings, feathers, and quacks. I do, however, see where an argument could be made that your er has allegedly violated Title VII based on sex, the ADA, and possibly FMLA as well.

If I were you, I'd want to consult an attorney before taking further action. I'd suggest you write up everything that has happened in detail, list any documentation you have, and list anyone who could substantiate any of your claims.

Just as a little side note, I would definitely seek out legal counsel, as suggested by MP, but remember this...
discrimination is extremely hard to prove, so if there are not people willing to substantiate your claims, it is simply a case of your word against the previous employer. Keep this in mind when you are gathering all the facts together.

>>I did tell a confidant who I worked with, but he would probably not defend me if it were me or his job.<<

Regardless of how great you may have done for the company, you are probably working as an "at-will" employee, which means they can let you go at any time.