Mid-1700s: England is a largely agricultural nation and is making great advances in agricultural productivity. Farmers are discovering the value of crop rotation, and better farming tools, such as ploughs and seed drills, are being developed.

Today: England is largely industrial and commercial and imports most of its food. The economy is based on transportation, communications, and the production of steel, petroleum, coal, and electricity.

Mid-1700s: England is ruled by King George II and his appointed prime minister, Sir Robert Walpole. The king rules a farflung empire that includes not only colonies in America, India, and elsewhere but also parts of Germany, where he spends much of his time. Walpole, therefore, has great power and authority in England.

Today: England is ruled by Queen Elizabeth II and Prime Minister Tony Blair, leader of the Labour Party. The role of the monarch has...