On February 1849, Leopold II had to concede Tuscany to the triumvirate made up of Montanelli, Guerrazzi, Mazzoni. Two months later, Austria restored him to the throne, but Leopold II was coldly greeted by his subjects, who accused him of having brought the Austrian army with him. The order to keep numerous soldiers in Florence and garrisons in almost every town of the Grand Duchy came actually from Vienna, as well as the repeal of the constitution, which caused the hostility of those Florentines who once had supported him.
On April 1859 a huge demonstration, headed by the republican Giuseppe Dolfi, convinced Leopold II to leave Florence. The Grand Duchy was now in the hands of the moderates, who voted Bettino Ricasoli as head of the interim government. On March 1860 Tuscany voted the annexation to the Italian Kingdom with 366.571 votes against 19.869.
The unification brought about new and urgent problems to solve, such as legislative, administrative and customs reforms, the creation of a National Army, a more widespread network of roads and railways, the organizing of a scholastic system, and so on: a demanding program, which overshadowed the reclamation of marhes.
Finally, in 1884, thanks to an inquiry by Stefano Joncini, the parliament focused its attention to the Maremman marshes and immediately decided to continue the former project. In a few decades, a deeper knowledge of the problem and improved technical skills, turned all Tuscan marshes into fertile lands.
In the meantime, Charles Louis Alphonse Laveran discovered the parasitic nature of malaria, showing that the disease was spreaded by a mosquito, the Anopheles, which lays its eggs in stagnant waters.
Once the cause was discovered, safeguards were adopted, from screen doors and curtains, to the populating of rivers with fish which fed themselves with mosquito eggs, or by preventing and curing the disease with the help of quinine.