Elected as the first (1848–1856) and seventh (1872–1876) president of Liberia after independence, he was the first man of African descent to govern the country, serving previously as governor from 1841 to 1848.

[3] The family moved to Petersburg, an industrial city on the upper James River with a substantial population of free people of color.

As a boy, Joseph began to work in his stepfather's business, handling goods on a flatboat that transported materials from Petersburg to Norfolk, Virginia on the James River.

Although Roberts was educated and a relatively successful merchant by the time he and his family emigrated, the restrictions in Virginia on free people of color played an important role in his decision.

[1] Several years before leaving for Liberia, Roberts established a business with his friend William Nelson Colson from Petersburg.

Roberts made several trips to the United States, including stops in New York, Philadelphia, and Richmond as a representative of the firm.

[2] During this time, Joseph's brother, John Wright Roberts, entered the ministry of the Liberian Methodist Church.

After starting as a trader, the youngest brother, Henry Roberts, studied medicine at the Berkshire Medical College in Massachusetts.

One of his responsibilities was to organize militias to travel to the interior to collect taxes from the indigenous peoples and put down their raids against areas under colonial rule.

Some coastal ethnic groups were converted to Christianity and learned English, but most of the indigenous Africans of the area retained their traditional religions and languages.

The slave trade continued illegally from ports along the Liberian coast, but the British Royal Navy along with that of the United States finally helped to close it down in the 1850s.

Roberts spent the first year of his presidency attempting to attain recognition from the United States, where it was opposed mainly by southern congressmen, as well as several European nations with neighboring colonies.

Roberts assisted the Maryland colony, and a joint military campaign by the two groups of African-American colonists resulted in victory.

During his presidency, Roberts expanded the borders of Liberia along the coast and made attempts to assimilate the indigenous people surrounding Monrovia into Americo-Liberian culture, largely through directed education and religious conversion.

Later in his career, his diplomatic skills helped him to deal effectively with the indigenous peoples and to maneuver in the complex field of international law and relations.

[2] After his first presidency, Roberts served for fifteen years as a major general in the Liberian Army, as well as a diplomatic representative of the nation to France and Great Britain.

[4] In 1871, President Edward James Roye was deposed by elements loyal to the Republican Party on the grounds that he was planning to cancel the upcoming elections.

In the 1860s and 1870s, escalating economic difficulties weakened Monrovia's dominance over the coastal indigenous populations, leading to several violent conflicts.

Conditions worsened following Roberts's second presidency, as the cost of imports was far greater than the income generated by exports of coffee, rice, palm oil, sugar cane, camwood, and timber.