4.2. People and Events: Students explain the historical significance of key people and events in order to examine the expansion of the boundaries and development of democracy in the United States.
4.2.1. Explain how early explorations affected the expansion of boundaries and development in the United States
4.2.2. Cite evidence to support the key contributions and influence of people in the history of the United States
4.3. People and Events: Students examine the impact of scientific and technological advances on the development of the United States.
4.3.1. Explain how inventions and new processes affected the lives of people, migration, and the economy of regions of the United States