The Isthmus Department or Department of Panama (Spanish: Departamento de Panama) was one of the departments of Gran Colombia and later of the Republic of Colombia. It was created in 1824 and covered the territory of what is now the country of Panama and some territories north.
After the Thousand Days War and the influence of the United States to build the Panama Canal the former Department of Gran Colombia separated from Colombia and became the Republic of Panama.
The region of Panama was part of the Spanish empire during the wars of independence against the Spanish. After the patriot victory at the Battle of Carabobo, Panamanians decided to join Gran Colombia. Up until this point, Panama had remained within the Spanish Monarchy and had avoided the troubles afflicting the rest of the Viceroyalty of New Granada. On November 28, 1821 Panama was voluntarily annexed to Gran Colombia under the Constitution of Cúcuta, which had been promulgated on August 30, 1819.
Francisco de Paula Santander as vice president on duty gave birth to the first Department of Panama which he also divided into two provinces the Province of Panama and the Province of Veraguas.