African nationalism began to rise in Northern Rhodesia after World War II. African welfare associations, founded before the war, developed rapidly into political organizations. In 1946, representatives from 14 welfare societies formed the Federation of Welfare Societies. In 1948, the federation was reconstituted as the Northern Rhodesia Congress. It became the North Rhodesian African National Congress (ANC) in 1951 under the leadership of Harry Nkumbula. In 1958, dissatisfaction with Nkumbula's leadership gave rise to a breakaway movement led by the party's secretary-general, Kenneth Kaunda. Kaunda formed the Zambia African National Congress, which was declared illegal the following year. In 1960, the United National Independence Party (UNIP) was formed under Kaunda's leadership. UNIP received a majority of the popular votes in the 1962 elections and formed the first government after independence. The ANC became the chief opposition party.
In 1967, the United Party (UP) was formed by Nalumino Mundia, a Lozi who had been dismissed from the cabinet in 1966. Its support came mainly from Barotseland in the southwest, where the UP promised to restore the power of the chiefs. After violence erupted in the Copperbelt, Kaunda banned the UP as a "threat to public security and peace," and Mundia and his principal officers were arrested. In August 1968, the UP was declared illegal. Mundia was released in 1969, joined the UNIP in 1974, and was named prime minister in 1981.
In the general elections of December 1969, the UNIP won 81 seats in the National Assembly, the ANC 23, and independents 1. Kaunda was reelected president. The elections were followed by violence and political unrest. At the opening of the new Assembly, the speaker refused to recognize the ANC as the official opposition. With the proclamation of a one-party state in December 1972, UNIP became the only legal party in Zambia. The ANC was assimilated into UNIP; the United Progressive Party, formed in August 1971, was summarily disbanded by the government, and its founder, Simon Kapwepwe, briefly arrested.
On 5 December 1973, the first presidential elections held under the new constitution brought the reelection of Kaunda to a third term with 85% of the vote. Voters also filled the 125 elective seats in the National Assembly. In 1975, the UNIP declared its ranks open to former followers of banned parties, but in 1978 candidacy was restricted to those with five years' continuous UNIP membership. National Assembly and presidential elections were held in December 1978, with Kaunda, again unopposed, receiving 80.5% of the vote. In the elections of October 1983, Kaunda's share of the total rose to 93%. A total of 766 candidates ran for the 125 Assembly seats.
After considerable social unrest in 1986 and again in 1990, the Kaunda government came under domestic and international pressure to end UNIP's monopoly in legitimate partisan activity. A Movement for Multiparty Democracy (MMD) was formed and led by trade unionists and defectors from UNIP. Finally, in December 1990, Kaunda signed into law a bill legalizing opposition political parties. In the new constitution adopted in August 1991, candidates are no longer required to belong to UNIP.
These changes paved the way to multi-party presidential and parliamentary elections on 31 October and 1 November 1991, the first in 19 years. The MMD's leader, Frederick Chiluba, easily won the presidency, 81% to 15% for Kaunda. The MMD got 125 seats to 15 for UNIP in the National Assembly. Kaunda and his family were harassed by the MMD, which forced Kaunda to step down as UNIP leader in August 1992. However, he returned a few years later to reclaim UNIP leadership. He briefly considered running on the UNIP ticket in the national presidential elections in 2001.
Since the legalization of multiparty competition, more than 30 parties have operated in the country. Parties include Agenda for Zambia (AZ), Forum for Democracy and Development (FDD), Heritage Party (HP), Progressive Front (PF), Movement for Multiparty Democracy (MMD), National Citizens Coalition (NCC), National Leadership for Development (NLD), National Party (NP), Patriotic Front (PF), Zambian Republican Party (ZRP), Social Democratic Party (SDP), United National Independence Party (UNIP), United Party for National Development (UPND), and the National Democratic Alliance (NADA). The United Democratic Party and the United Democratic Congress Party are headed by former top UNIP leaders. The National Party (also with prominent ex-MMD figures) was created in August 1993 and won four seats in the Assembly in 1993–94 by-elections. Within the MMD there is a breakaway group, the Caucus for National Unity, to root out corruption in government.
In elections held on 20 November 1996, President Frederick Chiluba and the MMD won over 85% of the available seats in the National Assembly. However, independent observers condemned the election as being rigged by the MMD.
In the election of 27 December 2001, Levy Mwanawasa was elected president with 29% of the vote to 27% for Anderson Mazoka, 13% for Christon Tembo, 10% for Tilyenji Kaunda, 8% for Godfrey Miyanda, 5% for Benjamin Mwila, and 3% for Michael Sata. In the legislative contest held the same date, eight parties won seats in the National Assembly. The MMD claimed 45.9% of the vote winning 68 seats, followed by the UPND with 32.4% and 48 seats, the UNIP with 8.8% and 13 seats, the FDD with 8.1% and 12 seats, the HP with 2.7% and 4 seats, the PF with 0.7% and one seat, the ZRP with 0.7% and one seat, and independents with 0.7% and one seat. Two seats were not determined. The next elections were due 2006.