Cross River State is a state in the South-South geopolitical zone of Nigeria. Named for the Cross River, the state was formed from the eastern part of the Eastern Region on 27 May 1967. The state has its capital as Calabar and is bordered to the north by Benue State, to the west by Ebonyi State and Abia State, and to the southwest by Akwa Ibom State while its eastern border forms part of the national border with Cameroon. Originally known as the South-Eastern State before being renamed in 1976, Cross River state formerly included the area that is now Akwa Ibom State, which became a distinct state in 1987. Of the 36 states, Cross River is the nineteenth largest in area and 27th most populous with an estimated population of over 3.8 million as of 2016. Geographically, the state is mainly divided between the Guinean forest–savanna mosaic in the far north and the Cross–Sanaga–Bioko coastal forests in the majority of the interior of the state. The smaller ecoregions are the Central African mangroves in the coastal far south and a part of the montane Cameroonian Highlands forests in the extreme northeast. The most major geographical feature is the state's namesake, the Cross River which bisects Cross River State's interior before forming much of the state's western border and flowing into the Cross River Estuary. Other important rivers are the Calabar and Great Kwa rivers which flow from the inland Oban Hills before flanking the city of Calabar and flowing into the Cross River Estuary as well. In the forested interior of the state are several biodiverse protected areas including the Cross River National Park, Afi Mountain Wildlife Sanctuary, and Mbe Mountains Community Forest. These wildlife reserves contain populations of Preuss's red colobus, African forest buffalo, bat hawk, tree pangolin, grey-necked rockfowl, and West African slender-snouted crocodile along with some of Nigeria's last remaining Nigeria-Cameroon chimpanzee, drill, African forest elephant, and Cross River gorilla populations. Demographically, Cross River State is inhabited by several ethnic groups, primarily the Efik of the riverside south and Calabar; the Ekoi (Ejagham) of the inland south; the Akunakuna, Boki, Bahumono, the Igbo (Isobo and Ikwo) and Yakö (Yakurr) of the central region; and the Bekwarra, Bette, Igede, the Mbube people and Ukelle (Kukele) of the northern region. In the pre-colonial period, what is now Cross River State was divided between its ethnic groups with some joining the Aro Confederacy while the Efik founded the Akwa Akpa (Old Calabar) city-state. The latter become a British protectorate in 1884 as the capital of the Oil Rivers Protectorate but it was not until the early 1900s that the British actually gained formal control of the entire area. Around the same time, the protectorate (now renamed the Niger Coast Protectorate) was incorporated into the Southern Nigeria Protectorate which later merged into British Nigeria. After the merger, much of modern-day Cross River became a centre of anti-colonial resistance during the Women's War and trade through the international seaport at Calabar. After independence in 1960, the area of now-Cross River was a part of the post-independence Eastern Region until 1967 when the region was split and the area became part of the South-Eastern State. Less than two months afterwards, the Igbo-majority former Eastern Region attempted to secede as the state of Biafra; in the three-year long Nigerian Civil War, Calabar and its port was hard fought over in Operation Tiger Claw while people from Cross River were persecuted by Biafran forces as they were mainly non-Igbo. At the war's end and the reunification of Nigeria, the South-Eastern State was reformed until 1976 when it was renamed Cross River State. Eleven years later, Cross River State was divided with western Cross River being broken off to form the new Akwa Ibom State. The state formerly contained the oil-producing Bakassi Peninsula, but it was ceded to Cameroon under the terms of the Greentree Agreement. As an agricultural state, the Cross River's economy partially relies on crops, such as cocoyam, rubber, oil palm, yam, cocoa, cashews, and plantain crops, along with fishing. Key minor industries involve tourism in and around the wildlife reserves along with the historic Ikom Monoliths site, Calabar Carnival, and Obudu Mountain Resort. Cross River state has the joint-thirteenth highest Human Development Index in the country and numerous institutions of tertiary education.
