After mediatisation, by way of the Principality of Aschaffenburg and the Grand Duchy of Frankfurt Orb eventually came to the Kingdom of Bavaria in 1814. Spa activities started as early as 1837. After the Austro-Prussian War of 1866, Bad Orb became Prussian in 1867. In 1884, a children's medical facility was founded by the brothers Friedrich Hufnagel and Wilhelm Hufnagel, which today is known as the Spessart-Klinik. After 1900, brine began to be used as an alternative medicine. In 1899 salt production ceased at Orb. Bad Orb was named a nationally certified spa town in 1909. The remaining salina today is used for medical treatments, especially inhalation and relaxation.