Final answer:
José de San Martín played a critical role as a military leader in the liberation of Argentina, Chile, and Peru from Spanish rule, securing independence for these countries as part of the broader South American independence movements.
Step-by-step explanation:
José de San Martín was a key figure in the liberation of South American countries from Spanish rule during the 19th century. Educated in Europe and trained militarily, he joined the independence movement and by 1816 had secured freedom for Argentina. Alongside Bernardo O'Higgins, San Martín led a daring assault across the Andes to Chile, achieving independence by 1819, before joining the fight for Peruvian independence, ultimately aiding in the liberation of much of South America. Additionally, San Martín and Simón Bolívar, known as the libertadores, worked toward containing royalist strongholds in Peru to secure the freedom of the continent from European colonialism