Concept:
The Garden City Movement was initiated by Sir Ebenezer Howard in England during the late 19th century.
The idea was to combine the advantages of urban and rural life by developing planned towns with green belts, self-contained communities, and balanced residential, industrial, and agricultural areas.
The first successful garden city established based on Howard’s principles was Letchworth Garden City in 1903.
Step 1: Identify the first garden city developed by Ebenezer Howard.
Ebenezer Howard proposed the concept of Garden Cities in his book:
\[
\textit{“To-Morrow: A Peaceful Path to Real Reform”}
\]
published in 1898.
Step 2: Analyze the given options.
• Welwyn -- Another garden city developed later in 1920.
• Letchworth -- First garden city established in 1903. \checkmark
• Red burn -- Not associated as the first garden city.
• Columbia -- Planned city in the USA, not Howard’s first garden city.
Therefore, the correct answer is:
\[
{\text{Letchworth}}
\]