History of Communications – In which decade was the electric telegraph invented and deployed? Select the best historical timeframe for the invention and early use of the practical telegraph.

Introduction / Context:
The electric telegraph revolutionized long-distance communication by transmitting coded electrical signals over wires. Its practical deployment predates the telephone and paved the way for modern telecommunications networks.

Given Data / Assumptions:

• The question seeks the decade of invention and early deployment.
• We refer to practical, operational systems rather than early laboratory experiments.
• Key figures include Samuel Morse in the United States and Cooke & Wheatstone in Britain.

Concept / Approach:
While prototypes emerged earlier, the 1840s saw practical telegraph lines established: Morse's line between Washington, D.C., and Baltimore opened in 1844, and Cooke & Wheatstone advanced their systems in the 1830s–1840s. Therefore, the 1840s best capture the period of invention-to-adoption for real-world communication networks.

Step-by-Step Solution:

Verification / Alternative check:
Historical timelines routinely list 1844 as the first long-distance telegraph message (“What hath God wrought”), anchoring the 1840s as the seminal decade.

Why Other Options Are Wrong:

• 1810s: Too early for practical electric telegraph lines.
• 1870s/1890s: Telegraph was already mature and widespread by then; the telephone (1870s) had appeared.

Common Pitfalls:
Equating early experiments with operational deployment, or confusing telegraph with later telephone milestones.

Final Answer:
1840s