Which resource would best support third-grade students in understanding causal relationships in Michigan history?

Letters from immigrants to Michigan would be particularly effective in supporting third-grade students' understanding of causal relationships in Michigan history because they provide personal narratives that illustrate the reasons why individuals moved to Michigan and how those movements influenced the state's development. These letters can reveal the motivations behind immigration, such as job opportunities, land availability, or escaping difficult situations, and show how such decisions impacted the broader historical context of the state.

Through reading and analyzing these letters, students can draw connections between individual experiences and larger historical trends, fostering a deeper comprehension of the cause-and-effect dynamics influencing Michigan's growth. The personal touch of first-hand accounts also engages students and helps them relate to historical figures, making the study of causal relationships more tangible and relevant.

In contrast, other resources like timelines and graphs may present information in a more abstract manner, lacking the personal context necessary to effectively illustrate individual motivations and their impacts on the state's history.