Steamships removed the message speed limit imposed by horses and sails, and telegraphy made communication almost instantaneous. Top state sizes expanded accordingly. Graphs superimpose the growth–decline curves of major post−1800 Engineer Empires. Britain became the largest empire ever (24% of world dry land area), but it lasted at more than half of its maximum size only for 110 years, comparable to nomad Xiongnu. State collapse in China also made Britain briefly the most populous of the world, due to its control of India. For most of the Engineer period Russia has been the largest and China (Qing and People’s Republic) the most populous. India’s population surpassed China’s in 2023. At the 1925 peak of European domination, 64% of Earth’s dry land area was ruled from Europe. It is now down to 21%, mainly Siberia. But European-stock Russia, USA, Canada, Brazil, and Australia remain part of the top seven, along with China and India. Population proportions differ. Since 1800, six to ten states have held more than 2% of Earth’s dry land area. Every half-century, three to four have entered or exited this category. By this pattern, 2000−2050 has been unusually quiet, up to now.