In the context of United States environmental history, what was a major contribution of John Muir?

Introduction / Context:
John Muir is a central figure in the environmental history of the United States and is often called the father of the national parks. His life and work are important because they show how one individual's passion for nature can influence government policy and public opinion. Many general knowledge exams ask about his major contribution, since this links to topics such as conservation, national parks and early environmental movements.

Given Data / Assumptions:
- The question asks for a major contribution, not every activity, of John Muir.
- The setting is United States history, especially conservation and national parks.
- The options include very different types of achievements: political, industrial and environmental.
- We assume the candidate knows that John Muir was a naturalist and environmental activist, not a president or railway engineer.

Concept / Approach:
John Muir devoted his life to exploring wild landscapes, writing about the beauty of mountains and forests, and campaigning to protect them from uncontrolled development. He co founded the Sierra Club and strongly influenced leaders such as President Theodore Roosevelt. His ideas contributed directly to the establishment and protection of national parks like Yosemite. Therefore, when choosing the correct option, we look for the description that emphasises wilderness preservation and the growth of the national park system.

Step-by-Step Solution:
Step 1: Recall who John Muir was: a Scottish American naturalist, writer and advocate of wilderness preservation.Step 2: Match this identity with the type of contributions likely to be connected with him, such as conservation and national parks.Step 3: Examine the options and note that only one talks about preserving wilderness and helping create the national park system.Step 4: Eliminate the option about drafting declarations of independence, which refers to leaders like Thomas Jefferson.Step 5: Eliminate the option concerning railway design, which belongs to industrial engineering rather than conservation.Step 6: Eliminate the option about serving as the first president, which clearly refers to George Washington, not John Muir.

Verification / Alternative check:
If you think of famous images of John Muir, he is often shown in mountain settings, walking with President Roosevelt in Yosemite or writing about nature. Textbooks highlight how his lobbying influenced the US government to create and expand protected areas. None of the standard historical narratives connect him with independence era politics, railway engineering or the office of president. This consistent portrayal in biographies and history courses confirms that his major contribution lies in wilderness preservation and national parks.

Why Other Options Are Wrong:
Option B is wrong because John Muir was not involved in drafting the historic declaration that announced US independence; that role belongs to figures like Thomas Jefferson and the Continental Congress. Option C is incorrect since Muir did not design the transcontinental railway; that achievement involved many investors, engineers and workers, but not him. Option D is also wrong because he never served as president and lived in a different era from the first presidents.

Common Pitfalls:
A common error is to confuse the names of many historic figures when reading quickly, especially if the exam includes several questions about different American leaders. Another pitfall is to assume that anyone important must have held high political office, when in fact many influential people, such as scientists, writers and activists, shaped history without being presidents or prime ministers. Remembering one key phrase for John Muir, such as father of national parks, can help avoid this confusion.

Final Answer:
A major contribution of John Muir was that he led the movement to preserve wilderness and helped create the national park system.