Wireless milestones: Identify the decade of the first transatlantic radio broadcast. Full question: In which decade did the first successful transatlantic radio transmission occur (Marconi's signal across the Atlantic)? Choose the correct decade.

Given data

• Event: First transatlantic radio transmission/broadcast.

Reasoning Guglielmo Marconi received the first transatlantic radio signal (the Morse letter "S") in 1901, placing the milestone in the 1900s decade.

Verification/Context Demonstrations continued in the early 1900s, establishing long-distance wireless communication well before regular voice broadcasts became common.

Final Answer 1900s.