Final answer:
The flag may be displayed at half-staff for 30 days following the death of a former president in the United States.
Step-by-step explanation:
In the United States, when a former president dies, the flag may be displayed at half-staff for a certain period of time as a sign of mourning and respect.
According to the United States Flag Code, the flag is typically displayed at half-staff for 30 days following the death of a former president. However, this period can vary depending on the wishes of the current president or state governors.
For example, when President George H.W. Bush passed away in 2018, President Trump declared a 30-day period of mourning, during which the flag was flown at half-staff.