This study aims to explore the linguistic structures and the concept of power underlying King's speech through structural - emotional perspectives, adopting the dual lens of Functional Discourse Grammar (FDG) and Conceptual Metaphor Theory (CMT). FDG provides a robust framework to examine the functional structures of King's language at the syntactic, semantic, and pragmatic levels, while CMT allows for a nuanced understanding of how metaphors in the speech contribute to the construction of power, social change, and collective identity. The study employs a mixed quantitative -qualitative research method. Findings reveal that King prefers using linguistic structures at the phonological and morphosyntactic levels more than at the representational and interpersonal levels. He further emphasizes concepts of power using 15 instances of metaphors in his speech. His masterful employment of linguistic structures and metaphors brings ideology, stance, and power to his political discourse, grasping the attention of his audiences and making significant efforts in demanding rights for freedom, justice, equality, and job opportunities, as well as in promoting business in the Black community, which is being oppressed by the White Society. Future research could further explore King's linguistic structures and metaphors by utilizing digitalization in the modern era.