Who is the person who led Argentina to independence in 1816?

No one person led Argentina to independence in 1816. Independence was very much a collective effort on the part of the General Congress, a legislative body which had been summoned after the revolution of 1815. It was the Congress, as a single entity, that declared independence from Spain, citing conditions in Europe in support of its momentous decision. The Congress declared that Spanish sovereignty over the Americas ended with Napoleon's deposition of Ferdinand VII as King of Spain in 1808 and that, therefore, Argentina was no longer beholden to its colonial overlords.
The President of the General Congress during the declaration of independence was Francisco Narciso de Laprida, a lawyer and deputy from the western Argentinian province of San Juan. Although he presided over a generally unified Congress at first, cracks soon began to appear between two main factions: the Unitarian Party (of which Laprida was a member), which favored strong, centralized government; and the Federales, who believed that ultimate sovereignty in the newly independent nation should reside in the provinces.