In 1959, Singapore achieved full internal self-government from Britain. This was a significant milestone in its journey towards independence.
Key events related to this period include:
 * May 30, 1959: The general election was held for the new Legislative Assembly. The People's Action Party (PAP), led by Lee Kuan Yew, won a landslide victory.
 * June 3, 1959: Singapore officially became a self-governing state, and this date was celebrated as National Day between 1960 and 1963. The new constitution was adopted, establishing the position of Yang di-Pertuan Negara (head of state) and Prime Minister (head of government).
 * June 5, 1959: Lee Kuan Yew was sworn in as Singapore's first Prime Minister, heading the first fully elected government under the new constitutional framework.
 * December 3, 1959: Singapore's national symbols – the National Flag, State Crest, and National Anthem – were unveiled during the installation of Encik Yusof bin Ishak as the first Malayan-born Yang di-Pertuan Negara.
To commemorate this historic event, a First Day Cover (FDC) would have been issued for the stamps released to mark the inauguration of Singapore's self-government. These stamps, and accompanying FDCs, are collector's items that reflect this crucial period in Singaporean history. The stamps issued during this self-governing period (1959-1963) were inscribed "State of Singapore."