The United States is located in the northern hemisphere.

The diagram shows the Earth's position relative to the Sun at different times of the year. In the northern hemisphere, the United States experiences the most direct sunlight during the summer solstice. This occurs around June 21st when the Earth's tilt causes the Northern Hemisphere to be inclined towards the Sun. At this time, the Sun's rays hit the Northern Hemisphere more directly. In the diagram, position C represents the location of the Earth during the summer solstice, where the Northern Hemisphere receives the most direct sunlight.

References

Integrated Physical Sciences: Earth's axial tilt and seasonal changes.

Diagram interpretation of Earth's position relative to the Sun.