Short answers, pulled from the story.
Pope Pius VII, born Barnaba Niccolò Maria Luigi Chiaramonti on the 14th of August 1742 in Cesena, served as head of the Catholic Church from the 14th of March 1800 until his death on the 20th of August 1823. He was also a Benedictine monk and theologian before his election to the papacy.
The Concordat of 1801 was a treaty negotiated by Cardinal Secretary Ercole Consalvi with Napoleon, then First Consul of France. It acknowledged Catholicism as the religion of the great majority of French citizens, gave the pope the right to depose bishops, required the state to pay clerical salaries, and required the Church to surrender claims to lands seized after 1790. Sunday was reestablished as a festival day effective Easter Sunday, the 18th of April 1802.
Napoleon had France occupy and annex the Papal States in 1809 after Pius VII refused to align them with Napoleon's Continental System. Pius VII responded with the papal bull Quum memoranda, excommunicating Napoleon. French forces then seized the pope, transporting him first to Savona and later to France, where he remained until 1814.
Yes. Pius VII joined the declaration of the 1815 Congress of Vienna urging suppression of the Atlantic slave trade. He wrote to King Louis XVIII of France on the 20th of September 1814 and to King John VI of Portugal in 1823, defining the sale of people as an injustice to human dignity and urging both monarchs to use their authority to end the practice.
Pius VII established new dioceses in the United States in 1808 for Boston, New York City, Philadelphia, and Bardstown. In 1821, he added dioceses for Charleston, Richmond, and Cincinnati. He also praised the United States for its military campaign against the Barbary pirates, declaring that Americans had done more for Christianity than the most powerful Christian nations had done in ages.
Pius VII universally restored the Society of Jesus on the 31st of July 1814, signing the papal bull Sollicitudo omnium ecclesiarum. He had begun the process earlier with the brief Catholicae fidei on the 7th of March 1801, which recognized the Jesuits in the Russian Empire and named Franciszek Kareu as their first superior general there. He appointed Tadeusz Brzozowski as the order's Superior General upon the full restoration.