The first and most notable construction was that of the Gradaščević family castle. The fort had existed for decades and was subject to extensive renovations since the time of Mehmed-kapetan in 1765. Husein's father Osman and brother Murat had done some work as well, in 1808 and 1818 to 1819 respectively. However, the exact nature of Husein's contribution to the complex is unknown. The castle's tower has long been associated with Husein but architectural evidence points to the tower existing alongside the rest of the complex from earlier times. It seems likely that Husein was merely responsible for a significant renovation of the tower that lingered in the people's memory.
Husein was certainly responsible for a completely new castle built during his rule. By all accounts, this was a large project, which included the construction of an artificial island surrounded by a moat up to 100 meters wide and of a great depth. The castle was named Čardak and the surrounding village quickly derived its name from it. The walls were of an oval shape, the entire structure being seventeen meters long and eight meters wide. The complex and area also included a mosque, wells, a fishery, and hunting grounds.
Within the Gradačac city walls Husein's most significant contribution to the city was the clock tower (Bosnian: sahat-kula) which was built in 1824. The object's base is 5.5 by 5.5 meters, while the height is 21.50 meters. It was the last object of this type to be built in Bosnia.
Some 40 to 50 meters outside the city walls lies Husein's greatest architectural contribution to Gradačac: the Husejnija mosque. Built in 1826, it features an octagonal dome roof and a particularly high minaret of twenty-five meters. Three smaller octagonal domes are found above the verandah. Islamic decorations and artistry are seen on the door and surrounding wall as well as the interior. The entire complex is surrounded by a small stone wall and gate.
Husein's rule in Gradačac was also notable because of his tolerance towards the Christian populace under his jurisdiction; both Catholic and Orthodox. Though social norms of the time dictated that the Ottoman sultan's official approval was necessary for the construction of any non-Islamic religious buildings, Husein approved the construction of several such buildings without it. A Catholic school was built in the village of Tolisa in 1823, followed by a large church that could hold 1,500 people. Another two Catholic churches were built in the villages of Dubrave and Garevac, while an Orthodox church was built in the hamlet of Obudovac. During Husein's captaincy, the Christians in Gradačac were known to be the most satisfied in Bosnia.
The year 1827 marked Husein's entrance into the greater Bosnian political scene. This was largely due to the impending Russo Turkish War and his role in preparing the defense of the boundaries of the Province of Bosnia. Upon receiving orders from the Bosnian vizier Abdurahim-paša, Husein mobilized the Gradačac populace and strengthened his defenses. During talks held in Sarajevo between the vizier and the country's captains, it is said that Husein stayed the longest to discuss strategy. He was appointed commander of an army that he was to mobilize from the lands between the Drina to the Vrbas. By all accounts, he did a satisfactory job. However, in mid-June 1828, Husein had to rush to Sarajevo with a small accompanying force to get the vizier to safety following a revolt among the troops.
By 1830, Husein had risen to new political heights as he was able to speak on behalf of all (or at least most of) the captains of Bosnia. At that time, he was coordinating the defense of Bosnia against a possible invasion by Serbia, as well as taking it upon himself to address Austrian authorities and warn them against any incursion across the Sava. The authority he wielded in the later years of his captaincy in Gradačac explains the great role he was to have in the years to follow