Yes, these sentiments definitely existed in the mid-nineteenth century. Regionalism in Spain has long historical roots, informed, as your question implies, by the legacies of the medieval kingdoms and by the original "composite" structure of the Spanish monarchy (before the Bourbon ascendancy). But since your questions asks more about the nineteenth century, I will stick to that.

Spanish national identity was still very fragile by the nineteenth century. Most Spanish historians agree that the so-called War of Independence (1808-1814) against the French marked a turning point in the development of Spanish nationalism- when the Cortes of Cadiz convened to draw up the Constitution of 1812, they defined the Spanish empire as a nation of citizens rather than subjects, whose sovereign derived his legitimacy from the Spanish people. This is in stark contrast to previous centuries where Spanish identity (to the extent that it even existed) was defined by cultural Catholicism rather than national origin. By redefining a Spaniard as a citizen, this was a big step towards the creation of a modern "Spanish" national identity.

However, a lot of Spanish historians differ on whether common Spaniards shared and maintained a strong national identity with Spain's liberal elites. The consensus seems to be that Spanish national identity was very weak, even in the early to mid nineteenth century (and, arguably, today, of course). This means that a Spaniard in the mid-nineteenth century would have probably identified more with his/her province than with their nation, although this varied greatly among region. Historically, regions like Navarre, the Basque Country, Galicia, Catalonia, and to some degree, Valencia have had stronger regional nationalisms than regions like Castille, Asturias, or Leon. In the case of the latter grouping, inhabitants of these regions were more likely to identify as "Spaniards" because of the historical identification the Spanish crown made with the Kingdoms of Castille and Leon. Spanish identity was often defined in Castilian terms and Castilian symbolism.

Arguably, the earliest manifestation of a regionalist political movement in the nineteenth century was in Carlism. The Carlists were a group of conservative pseudo-nationalists from Navarre and the Basque Country who took up arms against the Spanish crown in 1833. The Carlists rose in protest over a disputed claim to the throne- Ferdinand VII had passed his throne on to his daughter, Isabel II, whom the Carlists saw as an illegitimate heir because she was a woman. The Carlists argued that her reign violated Spain's salic law of succession, which allowed only a male heir to inherit the throne. Since Ferdinand's brother, Carlos, was the next of kin according to that law, they were dubbed the "Carlists." However, the Carlists did not only advocate for a different monarch. Carlism called for the return of a Spanish monarchy similar to that of the Habsburgs and of the Old Regime, which had granted significantly greater autonomy to the Navarrese and Basque nobility. They hoped to restore the laws of the regional nobility, the fueros. The Carlists found their greatest sympathy in the Navarrese, Basque, and Catalan countrysides, and waged a protracted civil war against the Spanish state for six years. They rose again in 1846 and then one more time during the "Democratic Sexennial" in 1868 when radical liberals took control of the government.

We have to realize that Spain in the nineteenth century was undergoing a liberal revolution. While liberalism in Spain manifested itself in a variety of forms, both radical and conservative, almost all of Spain's liberal factions agreed that regionalism was a threat to the stability of the Spanish nation. Therefore, in a great number of cases, laws were passed that stripped regions of their autonomy or expanded the powers of the central state. This created a climate of bitter resentment among the regions that had been historically more independent. Between 1808 and 1874, Spain had gone through multiple civil wars, coups, and civil conflicts. While these conflicts would be far too many to name, in almost each case, regional autonomy was typically a critical issue at play in the outbreak of violence. By 1874, the Spanish state responded to a century of violence by creating a new political system designed to temper passions- power was to be exchanged every few years between liberal and conservative factions and political participation of the masses discouraged. This system, known as the Restoration system, was particularly fearful of regional concerns and of the possibility of another uprising from common people, whom political elites deemed "unworthy" of Spanish democracy.

In response to this system of exclusion, we begin to see the creation of Spain's first regionalist political parties. The first "Catalan nationalist party" was the Lliga Regionalista, a conservative organization founded in 1893 that was politically similar in its goals to Carlism. Accompanying this group were the remnants of Spain's federal republican movement- between 1820-1874, Spanish republicans tended to favor a federal system that respected regional autonomy. This included prominent figures like the Catalan Francisco Pi y Margall, who was President of Spain's First Republic during its brief lifespan as a federal republic in 1873. However, after the fall of the First Republic, the republicans and the Spanish left abandoned nationalism for a time.

In conclusion, the nineteenth century was a chaotic period in Spanish history in which questions about regional and national identity were confronted explosively, often with violence and war. In all the cases that I've listed, the regionalist movements tended not to favor outright independence but merely greater autonomy. It's shocking to consider that a mere call for greater autonomy could result in such great bloodshed but such was the case. As you can imagine, this radicalized the regionalist groups over time, so that by the early twentieth century, especially by the 1930s, some regionalist groups were going as far as calling for a totally independent nation. After Franco, this was practically a done deal.