er areas south
of the Antarctic Circle. Not until 1840 was it established that
Antarctica was indeed a continent and not just a group of islands.
Several exploration "firsts" were achieved in the early 20th
century. Following World War II, there was an upsurge in scientific
research on the continent. A number of countries have set up
year-round research stations on Antarctica. Seven have made
territorial claims, but not all countries recognize these claims. In
order to form a legal framework for the activities of nations on the
continent, an Antarctic Treaty was negotiated that neither denies
nor gives recognition to existing territorial claims; signed in
1959, it entered into force in 1961.

Antigua and Barbuda
The Siboney were the first to inhabit the
islands of Antigua and Barbuda in 2400 B.C., but Arawak and Carib
Indians populated the islands when Columbus landed on his second
voyage in 1493. Early settlements by the Spanish and French were
succeeded by the English who formed a colony in 1667. Slavery,
established to run the sugar plantations on Antigua, was abolished
in 1834. The islands became an independent state within the British
Commonwealth of Nations in 1981.

Arctic Ocean
The Arctic Ocean is the smallest of the world's five
oceans (after the Pacific Ocean, Atlantic Ocean, Indian Ocean, and
the recently delimited Southern Ocean). The Northwest Passage (US
and Canada) and Northern Sea Route (Norway and Russia) are two
important seasonal waterways. A sparse network of air, ocean, river,
and land routes circumscribes the Arctic Ocean.

Argentina
Following independence from Spain in 1816, Argentina
experienced periods of internal political conflict between
conservatives and liberals and between civilian and military
factions. After World War II, a long period of Peronist
authoritarian rule and interference in subsequent governments was
followed by a military junta that took power in 1976. Democracy
returned in 1983, and numerous elections since then have underscored
Argentina's progress in democratic consolidation.

Armenia
Armenia prides itself on being the first nation to formally
adopt Christianity (early 4th century). Despite periods of autonomy,
over the centuries Armenia came under the sway of various empires
including the Roman, Byzantine, Arab, Persian, and Ottoman. It was
incorporated into Russia in 1828 and the USSR i