Final answer:
Following his father's death, Mark Twain headed out West, where he became a journalist and later an editor, experiences which propelled his writing career and influenced his critical stance on social issues through his work.
Step-by-step explanation:
After Twain's father's death, Twain made the significant decision to venture out West, where his experiences would later become the backbone for his successful book, Roughing It!, published in 1872.
This move marked a turning point in his life, as Twain immersed himself in his work as a journalist and later rose to prominence as the editor of the Virginia City Daily Territorial Enterprise.
This period out West was critical in shaping Twain's career, leading him to become a renowned writer, journalist, and public speaker, leveraging his experiences to criticize societal issues like slavery and class hierarchy in his literature.