Plovdiv reached an agreement that the Principality of Bulgaria and Eastern Rumelia had a common government, Parliament, administration, and army. Today 6 September is celebrated as the Unification Day and the Day of Plovdiv. After the unification, Plovdiv remained the second most populous city in Bulgaria after the capital Sofia. The first railway in the city was built in 1874 connecting it with the Ottoman capital, and in 1888, it was linked with Sofia. In 1892 Plovdiv became host of the First Bulgarian Fair with international participation which was succeeded by the International Fair Plovdiv. After the liberation, the first brewery
History of Plovdiv In that period the richer citizens constructed houses, many of which can still be seen in the Architectural reserve "Old Plovdiv". The city was the capital of Rumelia Province between 1364–1864, and of Edirne province between 1864–1878 under Ottoman Rule. Plovdiv played a role in the struggle for Church independence. Plovdiv became the center of that struggle with leaders such as Nayden Gerov, Dr Valkovich, and Joakim Gruev. In 1836 the first Bulgarian school was inaugurated and in 1850 modern secular education began with the St Cyril and Methodius school. On 11 May 1858 the city celebrated the saints' day