The Countries

Liberia and Sierra Leone are two of the poorest countries in the world. According to the World Bank Liberia is the 4th country with the lowest GDP per capita ($813) and Sierra Leone the 10th ($1,473) . They are also among the countries with lowest Human Development Index. They were the countries affected most by the 2013 - 2016 Ebola outbreak with 10,666 cases and 4,806 deaths in Liberia and 14,122 cases and 3,955 deaths in Sierra Leone.

Sierra Leone

Population: 7,075,641

Area: 71,740 km2
Independence:  27 April 1961
Life Expectancy: 57.8 years

Sierra Leone became independent from the United Kingdom on 27 April 1961, led by Sir Milton Margai, who became the country's first Prime minister. The current constitution of Sierra Leone was adopted in 1991, though it has been amended several times.
From 1991 to 2002, the Sierra Leone Civil War was fought and devastated the country. The proxy war left more than 50,000 people dead, much of the country's infrastructure destroyed and over two million Sierra Leoneans displaced as refugees in neighbouring countries.
After the civil war the Ebola outbreak has affected the economic recovery.

Liberia

Population: 4,503,00

Area: 111,369 km2
Independence: 26 July 1947

The Republic of Liberia began as a settlement of the American Colonization Society (ACS), who believed black people would face better chances for freedom in Africa than in the United States. The country declared its independence on July 26, 1847. The black settlers carried their culture and tradition with them to Liberia. The Liberian constitution and flag were modeled after those of the U.S.
Liberia is the first African republic to proclaim its independence, on July 26, 1847 and is Africa's first and oldest modern republic. Liberia retained its independence during the Scramble for Africa. 
Five years of military rule by the People's Redemption Council and five years of civilian rule by the National Democratic Party of Liberia were followed by the First and Second Liberian Civil Wars. These resulted in the deaths of 250,000 people (about 8% of the population), the displacement of many more and shrunk Liberia's economy by 90%.
A peace agreement in 2003 led to democratic elections in 2005, in which Ellen Johnson Sirleaf was elected President. Recovery proceeds but about 85% of the population live below the international poverty line. Liberia's economic and political stability was threatened in the 2010s by an Ebola virus epidemic.