His first collection of poetry, Azul, was published in 1888, and his best piece would come 22 years after that.  
This author's innovative writing style was important in the development of poetry in both Spain and Latin America.  Born in 1867, he began traveling the world, and while in Buenos Aires organized a group of followers who established the Spanish-American modernist movement, a synthesis of romanticism, Parnassianism, and the symbolist movement.  His first collection of poetry, Azul, was published in 1888, and his best piece would come 22 years after that.  FTP, name this poet, whose best work was Poem of Autumn, born Felix Ruben Garcia-Sarmiento.
This author's innovative writing style was important in the development of poetry in both Spain and Latin America.  
Ruben Dario (Accept Felix Ruben Garcia-Sarmiento early)