I'm not being hired because of my height!?

Actually, it's NOT illegal, as Silhouette mentioned. It may be discrimination, but it doesn't fall under a protected area, so it's legal. As long as you are not discriminated against for race, gender, sexual preference (and a few other areas) it is legal. They can choose not to hire you for any reason, as well as to fire you for any reason (again, as long as it's not illegal discrimination). If may not be fair, but if you have the appearance of not being strong enough to do the job, they may not even take another look at you. Sorry...but don't give up! Take any classes or training options that come your way in the field. Then you have something else to offer them.

That sucks. It is illegal, but there is no way to prove it. And most states now protect the businesses and allow them to fire without provocation or refuse to hire someone while discriminating against them because it is so hard to prove. I tried to get a job and was denied 3 times before the employer told me to "cut my hair". My hair is to my knees. I told him I can braid it and put it in a bun and he said nope, cut it or no job. I chose to keep my hair.