MADRID — When seven men gathered in 1977 around a long green table in the Spanish Congress to write a Constitution for a new, democratic Spain, they spent a month, on and off, arguing over a single word.

It was just two years after the death of Gen. Francisco Franco, the Spanish dictator who had suppressed attempts to create regional autonomy.

The two Catalans at the table, Miquel Roca and Jordi Solé Tura, wanted the text to grant the right of self-government to Spain’s constituent “nations” — an implicit reference to Catalonia, Galicia and the Basque Country — Mr. Roca recalled in an interview. The other five, who included one of Franco’s former ministers, refused.

Eventually, they reached a compromise. The final text spoke not of nations — but of regions and nationalities.