The coastline was first charted by Spanish sailors in 1499, at which time the area was inhabited by Amerindians of the Arawak, Carib, and Warrau language groups. By 1746, the Dutch had established settlements on the Essequibo, Demerara, and Berbice rivers, and had withstood French and English attempts to capture and hold the area. The English occupied the settlements in 1796 and again in 1803, and gained formal possession at the Congress of Vienna in 1815. The three main settlements were united into the Colony of British Guiana in 1831. Slavery was abolished in 1834, and many blacks settled in cooperative villages or moved into the towns. Under pressure from planters, indentured servants were brought in from India to work on the sugar plantations. As a result, most of the sugar workers still are of Asian Indian origin, while the urban population is predominantly black. This division into ethnocultural groupings later became an important factor in Guyana's politics.
The change in British imperial policy after World War II was reflected in a new constitution introduced in 1953, providing for a bicameral legislature and universal adult suffrage. Elections were held in the same year. However, the British balked after the People's Progressive Party (PPP) captured 18 of the 24 elected seats. Six months after the elections, the UK suspended the constitution, charging Communist subversion of the British Guiana government. The colony was governed on an interim basis until 1957, when general elections again were held. Again, the PPP won, with 47.9% of the votes, and Cheddi Jagan, leader of the PPP, was named chief minister.
The colony was granted full internal self-government in 1961, following four years of continued economic and social progress. In elections held under a new constitution introduced that year, the PPP won 20 of the 35 seats in the newly established Legislative Assembly. In October 1961, Jagan, who had been named prime minister, went to Washington, D.C., to ask President Kennedy for US aid. Classified documents released in the mid-1990s reveal that, following Jagan's visit, Kennedy gave the CIA orders to destabilize Jagan's government. Kennedy also urged Britain to withhold full independence from Guyana until Jagan was removed from power. Through covert operations, the CIA incited a general labor strike and racial violence between Jagan's Asian Indian followers and his opponents, mainly of African descent. British troops were called upon to restore order, but the situation did not calm until July.
In the elections of December 1964, the PPP again emerged as the strongest party, but due to US efforts to undermine its power, it was unable to form a government alone. As a result, the British governor called upon the leader of the People's National Congress (PNC), Forbes Burnham, to establish a government.
The following November, an independence conference held in London approved the present constitution, and on 26 May 1966, Guyana became a sovereign and independent nation. Guyana was proclaimed a cooperative republic on 23 February 1970, the 207th anniversary of a Guyanese slave revolt led by Cuffy, still a national hero. The PNC ruled as majority party between 1968 and 1992, although not without controversy.
Guyana became known to the US public in 1978 in the wake of the Jonestown massacre. The government of Guyana, in an attempt to colonize the nation's wilderness regions, had in 1977 allowed an American, James Warren "Jim" Jones, to establish the People's Temple commune at what became known as Jonestown, in the northwest. Many in the United States had become concerned with developments in the commune, and US representative Leo J. Ryan had gone to Jonestown to investigate. He and four other US citizens were murdered at a nearby airstrip by Jones's followers. Then, on 18 November 1978, Jones and more than 900 of his followers committed suicide by drinking poisoned punch.
Between 1980 and 1985, relations between the PNC and opposition parties deteriorated sharply, as opposition parties charged harassment and fraud. The assassination in 1980 of Dr. Walter Rodney, a leading opposition figure, escalated the conflict. Under the administration of Forbes Burnham (1980–1985), human rights declined steadily. Burnham died in 1985 and was succeeded by First Vice President and Prime Minister Desmond Hoyte. The new president sought to improve Guyana's relations with non-Socialist nations, particularly the United States, and attempted the liberalization of the Guyanan economy.
However, by 1992 the country had grown tired of the PNC, and elected Cheddi Jagan of the PPP to the presidency in what was considered to be the first free and fair election since 1965. Jagan, who had been minority leader for years, received an impressive mandate with 53.4% of the vote, to 42.3% for the PNC. This translated to a solid 36 PPP seats in the National Assembly. Jagan had mellowed in the three decades since his ouster by the CIA, and in an ironic twist of history he was elected this time with the full support of the United States. Jagan served effectively as president until his death in March 1997 at age 78. Under Jagan's administration, Guyana was able to consolidate its massive foreign debts and began to enjoy sustained economic growth. Jagan's widow, Janet Jagan, was elected to succeed him in general elections held on 15 December 1997, but the opposition PNC challenged the legitimacy of the election. In spite of a Caricom audit that deemed the election fair, the opposition PNC, led by former prime minister Hoyte, continued to protest the presidency of Jagan throughout the early months of 1998, and there were demonstrations and other forms of civil unrest, as well as a 55-day strike by civil servants. On 14 August, the 78-year-old, US-born Jagan, suffering from a heart condition, stepped down, naming as her successor finance minister Bharrat Jagdeo, who, at age 35, became one of the world's youngest heads of state. Jagdeo went on to lead the PPP into a new electoral victory in the 1999 elections, with 53.1% of the vote. Jadgeo was reelected as Prime Minister and his party commands the support of 34 of the 65 members of the legislature.