Due to the early death of his father, upon turning 21 Joseph was immediately presented with his family’s impressive estate in Lincolnshire, in addition he was bestowed with the new titles as local squire and magistrate. Then in 1766, Banks was elected in to the Royal Society, and coincidently that same year, at 23, he went with Phipps aboard the frigate HMS Niger to Newfoundland and Labrador with the goal of studying natural history. As it turns out, Joseph came home with 34 new documented species of birds and a diary describing his expedition to Newfoundland, which would later be published. Almost immediately upon return home, Joseph set sail on his next adventure and joined James Cook on his maiden voyage on the Royal Navy/Royal Society scientific expedition to the south Pacific Ocean on HM Bark Endeavour, which lasted from 1768–1771. The journey drew to a close when Banks arrived back to England on July 12, 1771 and was immediately hit with instant fame. He intended to go with Cook on his second voyage; however unforeseen difficulties arose about Banks' scientific requirements on board Cook's new ship.
Soon after his return home he met and married Dorothea Hugessen in March of 1779. They settled down in a large estate in London which remained their primary residence for the remainder of their life. The two had no children; however they opened their house not only to his sister, Sarah Banks who resided with them, but they welcomed any passing through scientists, students, authors, and many distinguished foreign visitors of that time. That same year in 1779, Banks took a lease on an estate called Spring Grove, which he eventually bought outright in 1808. By 1781 Banks was made a baronet only three years after being elected president of the Royal Society. Then in 1788, he was nominated and elected Foreign Honorary Member of the American Academy of Arts and Sciences for all his work and discoveries during the two explorations he was a part of. Banks found time to serve as a trustee of the British Museum for 42 years. By the turn of the 19th century Banks health began to seriously deteriorate. From an early age he suffered from gout every winter, and by 1805 it became so serious he lost the use of his legs and had to be wheeled to his meetings in a chair, but his mind remained as vigorous as ever. Almost as if foreseeing his future, in May 1820 he handed in his resignation as president of the Royal Society, but withdrew it at the request of the council. Sadly, he passed away on June 19, 1820 at his Spring Grove home with his wife by his side. He was later buried at St. Leonard’s Church, Heston.