Explanation

• In April 1917, the United States entered World War I against the Central Powers.
• The main reason was Germany’s unrestricted submarine warfare in the Atlantic Ocean.
• German U-boats (submarines) attacked several ships, including American commercial vessels.
• This threatened U.S. trade and security, leading President Woodrow Wilson to declare war on Germany.

Additional information:

• World War I duration: 1914–1918
• Famous ship sunk by Germany: Lusitania in 1915
• Countries in Central Powers: Germany, Austria-Hungary, Ottoman Empire, Bulgaria
• War ended: 11 November 1918

Last verified on 11-03-2026

Explanation

• Total States: 50
• Federal District: Washington, D.C.
• 49th State: Alaska (1959)
• 50th State: Hawaii (1959)
• First State: Delaware (1787)

Last verified on 10-03-2026

Explanation

The “New START Treaty” was a nuclear arms reduction treaty between the United States and the Russia for the Further Reduction and Limitation of Strategic Offensive Arms.

This treaty entered into force on 5 February 2011.

Additional Information:

“New START” stands for New Strategic Arms Reduction Treaty

On 5 February 2026, the New START treaty officially expired.

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Explanation

• Donald Trump described the US operation in Venezuela in 2025–26 as a modern update of the Monroe Doctrine.

Additional information:

• The Monroe Doctrine was first articulated in 1823.
• It was by President James Monroe to oppose European interference in the Western Hemisphere.

Last verified on 10-02-2026

Explanation

Grand Canyon National Park

• Location: Arizona, U.S.A
• Established: 1919 as a National Park
• Famous For: Deep canyon carved by the Colorado River, colorful rock layers
• Size: Approximately 1,904 km² (735 square miles)

Additional information:

• The park is a UNESCO World Heritage Site.
• It is the one of the 7 natural wonders of the USA.

Last verified on 04-02-2026