Cape Verde wasn't just"given away". Portugal's African colonies fought a 13 years long war to gain independence. It was rooted in the existance of a seperate Cape Verdian (and Guinean) identity and mistreatment by the government in Lisboa. Cape Verde's independence movement was tied to that in Guinea per the African Party for the Independence of Guinea and Cape Verde (PAIGC) which fought in the colonial war, even though fighting was mainly done on the continent.

Cape Verde is a nation state. Cape Verdians have an identity independent of the Portugese. It is inhabitated by a so called creole people (incidentally also calling themselves kriolu), colloquially speaking a creole language.

That is because a majority of the population has it's roots in a mixture of of european colonists and slaves from africa, leading to a majority biracial people with distinct ethnic identity. It is the most miscegenated former colony of Portugal.

The islands were struggling heavily under later Portugese rule, both with regular droughts and famines kicking in and the island's economic inviability in face of the ending slave trade. While there was less racial prejudice against the islanders than against mainland african Portugese subjects due to their usually lighter skin colour, they were still treated worse than white mainland Portugese people.

This relatively better treatment though made for a more educated populace and a larger strata of competent civil and military personell in highest functions, which could carry a revolution and the nation-building thereafter. Cape Verdians, apart from administering the islands themselves, were also influential in all west african Portugese territories, especially Guinea. This lead to their later combined independence struggle and short-lived political union.

These people usually studied in Europe and were engaged in Marxist thought, as an answer against the Salazar dictatorship in Portugal. PAIGC initally sought to achieve this with non-violent resistance.

The authoritarian regime in Lisboa though refused enter negotiations with their colonies. Massive, violent, anticolonial sentiment emerged in Guinea after the Pidjiguiti massacre of 1959 which basically removed any chance at non-violent reconcilation with Portugal. The resulting armed strugle and war achieved the independece of Cape, Verde and Guinea which initially were ruled together by PAIGC, a union which couldn't and didn't last.

Sources:

• The preamble of the 1992 constitution
• Patrick Chabal, A History of Postcolonial Lusophone Africa
• Maria Eugenia Mata, Social cleavages in the last Portuguese colonial empire

E: I'm bad at grammar.