What is the largest freshwater lake in the world, by surface area, contained entirely inside the borders of one country?

The correct answer is Lake Michigan in the USA. The lake covers four states, Michigan, Wisconsin, Illinois, and Indiana, and has a total surface area is 22, 404 sq. mi. It breaks down into 13,237 sq. mi. in Michigan, 7,358 sq. mi. in Wisconsin, 1,576 sq. mi. in Illinois and 234 sq. mi. in Indiana. It is 307 mi. long by 118 mi. wide with a shoreline of 1,640 mi. It's depth ranges from 46 fathoms 3 feet (279 feet) to 153 fathoms 5 feet (923 feet). It's total volume is 1,180 cubic miles of water.

Lake Baikal is located in Russia and is the largest lake in the world by volume. It has a surface area of 12,248 sq. mi.

Lake Victoria is the largest lake by area in Africa and covers three countries, Uganda, Kenya, and Tanzania. The lake also has a surface area of 26,600 sq. mi.

Great Slave Lake in Canada is the deepest lake in North America. This lake has a surface area of 10,502 sq. mi.

Some interesting facts about the lakes. Lake Baikal is 5,670 cu. mi. of unfrozen fresh water or approximately 20% of the world's supply. Lake Baikal is home to many plants and animals that exist nowhere else in the world.

Lake Victoria, while having a larger surface area than Lake Michigan, covers three countries instead of just one. But is also the world's largest tropical lake.

Great Slave Lake is over 336 fathoms deep and has an ice road connecting the cities of Dettah and the capital of the Northwest Territories, Yellowknife. it is also fed by 30 different rivers.