Final answer:
The missing phrase in the First Amendment is 'to petition the government for a redress of grievances.' This phrase signifies the right of the people to make requests, complaints, or grievances to the government and seek redress or resolution.
Step-by-step explanation:
The missing phrase in the First Amendment to the United States Constitution is 'to petition the government for a redress of grievances.' The First Amendment guarantees several fundamental rights, including freedom of religion, speech, press, assembly, and the right to petition the government. This phrase signifies the right of the people to make requests, complaints, or grievances to the government and seek redress or resolution.