1900 (year) — overview and historical context

Calendar and chronological notes

1900 illustrates an important calendar distinction. Under the rules of the Gregorian system the year was not a leap year because century years are leap years only when divisible by 400; this technical classification is often called a common year. By contrast, the older Julian calendar treated 1900 as a leap year, a difference that affected date alignment between regions that had not yet adopted the Gregorian reform. Debates about when a century or millennium begins meant that although 1900 ended the ordinal nineteenth century, popular celebrations occasionally treated it as the start of a new era.

Notable events

• International tensions and conflicts continued: the Boxer Rebellion in China and the Second Boer War in southern Africa remained prominent diplomatic and military concerns.
• In the United States the presidential election and political developments reflected industrial and overseas policy debates.
• The devastating Galveston hurricane, one of the deadliest U.S. storms on record, struck in 1900, prompting changes in coastal planning and emergency response.
• Paris hosted the Exposition Universelle and the 1900 Summer Olympics, showcasing new technologies and international exchange.

Context and significance

Technological advances such as expanded electrical networks, early automotive and wireless experiments, and industrial organization continued to reshape everyday life. Cultural movements like Art Nouveau and evolving scientific institutions reflected shifting tastes and priorities. The year also underscores how calendar systems (Gregorian calendar vs. Julian calendar) and periodization (the end of the 19th century) influence how societies remember and classify historical time.

Viewed together, the political events, natural disasters, international exhibitions, and calendar technicalities of 1900 make it a useful focal point for understanding the transition from the 19th to the 20th century.