*and was handed over two years later
Hong Kong and Macau were the two largest major European colonies in China. When Hong Kong was given to China, it was viewed as a major turning point in world history. Prince Charles himself referred to it as the official end of the British Empire. Since then, Hong Kong has been a hotbed of controversy on the world stage due to China's actions in the city (as most should know if they follow the news lately).
Macau existed centuries longer than Hong Kong (it was actually formed during the Ming Dynasty), but in contrast with Hong Kong it seems like it was not as big a deal when it was given to China. Why is this? Even today compared to Hong Kong things seem to be much more "relaxed" for lack of a better term. Both are 'Special Administrative Regions" within China and hold a great deal of autonomy, but it is rare to see a major news story centered around China "cracking down on Macau" like you do in regard to Hong Kong. Why is this?
The short answer is that the handover of Macau was far less of a break between colonialism and native rule. Since 1966 and the 12.3 incident (when leftist activists stormed Macau), Macau was a colony only on paper—the Portuguese colonial administration failed to handle the leftist riots and acquiesced to Chinese influence (the governor signed an apology under a portrait of Mao Zedong). From 1966 forward, the colonial administration lost the will to govern, and actually offered to return Macau on several occasions (the Chinese refused). Portuguese troops were withdrawn in 1974, and Macau was known as a “half-liberated zone” (半個解放區). By 1999, Macau had been effectively Chinese controlled for over 30 years.
In Hong Kong things were very different. The Hong Kong colonial administration successfully dealt with the 1967 leftist riots, and reformed Hong Kong in such a way that gained the support of the local population. Its economy also grew at a miraculous rate through the 70s and 80s. By 1997, Britain was handing over one of the most successful cities in Asia to the Chinese — a city that, to a large extent, fuelled China’s own economic boom post-1979. Given the status of Hong Kong, its handover attracted far more attention and significance.
Essentially, Macau was quietly handed back as a under-developed city where the colonial administration had lost real power for over 30 years. Hong Kong was handed back as the centre of Asian finance with extremely developed infrastructure and governance structures.