I, too, sing America.

Hughes corrects Walt Whitman's image of America;
claims an equal place for the negro
the right to "sing too", to exit, have a proper share in American life to be considered a fully-fledged American

I am the darker brother

They send me to eat in the kitchen when company comes

they don't want to be seen with him;
kitchen - where the servants are (the socially inferior)
he feels himself at the mercy of his white master, of
contemporary society

but I laugh,

pretends not to mind

and eat well,

convinced that future will be his, remains passive

and grow strong.

wait and see

Tomorrow

contrasts the place of the American negro in the American society of today and tomorrow

I’ll sit at the table

a shared meal - expression of brotherhood
social acceptance and equality; religious connotation
Jesus shard bread and wine with his disciples

when company comes.

repetition intensifies our awareness of the change in the position of the negro; social equality

Nobody’ll dare
say to me,

slightly threatening tone
he has helped to fight America's wars

"Eat in the kitchen"
then.

he is no longer willing to take orders from white bosses

Besides, they’ll see

last four lines imply that the negro will gain his rightful position in America

how beautiful I am

latest fashion?

and be ashamed,-

his former masters, the white race will be ashamed

I, too, am America