Linked from
The 26 pages that link to Federation of Malaya, each with the reason it gives.
MalaysiaBroader topic: It became the core of the later Malaysian federation.
Malay PeninsulaBroader topic: It was the immediate predecessor of modern Malaysia on the peninsula.
Malayan UnionBroader topic: It was the direct constitutional successor to the Union.
UMNOBroader topic: UMNO helped negotiate the federation that replaced the union it had opposed.