How is Crooks's statement about "wanting rights" ironic in Of Mice and Men?

An example of Crooks, the African-American stable buck, earnestly defending his rights is found in Chapter 4 of the novel Of Mice and Men. 

There is a lot of irony about Crooks "wanting rights" in this chapter. 

The location of Crooks bunk is quite telling of his status when it comes to rights. The man is sent to live out in the stables next to the horses and other animals. The telling aspect of this is that, not only is Crooks considered a lesser human by being shut away from the barracks, he is likened to an animal since this is why he is sent to live. This is the first of many ironies surrounding his "wanting rights": his most basic human needs (sleep, shelter, companionship) are being violated even while he demands rights.

Crooks keeps medicine in a wooden apple box. These medicines are for both the horses and himself. Again, this symbolically likens Crooks to an animal as it seems that he takes care of himself with what he has for the horses. Ironically, it was a horse that kicked Crooks so fiercely that he was left crooked.

Crooks keeps to himself in hopes that people will reciprocate by leaving him alone. Being black and disabled, he has received a rare chance by being allowed to keep a job and home at the farm. However, that does not set him free from the prejudices and violation of his rights others. By keeping to himself, he expects that his right to be left alone will be respected. 

When Lennie busts in Crooks's room, a few statements make it quite obvious that Crooks is demanding "rights." Crooks says: 

"You got no right to come in my room. This here's my room. Nobody got any right in here but me."

Given the location of his stable room and the time and place of the setting (when his rights have been won but not yet lawfully supported), this demand for his rights is ironic--and quite saddening to the modern reader--because, while demanding and "wanting rights," he has no rights.

When Lennie says he was just following the light in Crooks's room, the latter says: 

"Well, I got a right to have a light. You go on get outa my room. I ain't wanted in the bunkhouse, and you ain't wanted in my room."

This is all ironic. Not only is this an assertion of his own rights, but he also takes the initiative to say which rights the others do not get to have when it comes to him. In order for him to be respected, Crooks has to defend himself because no system and no cultural norm has yet acknowledged his full humanity (this is true even though Abraham Lincoln and the Union Army dedicated the victory of the Civil War to the freedom, liberty and equality of men like Crooks).