1. Parole: This is the release of a prisoner temporarily or permanently before the completion of their sentence, on the promise of good behavior. It usually involves some conditions which the parolee must abide by. The paperwork includes documents such as Parole Agreement Form, Request for Parole Review, etc.

2. Compassionate release: This allows for the release of prisoners due to medical or humanitarian reasons, such as terminal illness. Forms include Request for Compassionate Release, Medical Release Form, etc.

3. Commutation of Sentence: This reduces the length of a sentence, but it doesn't change the fact of conviction, like pardoning. Forms include Petition for Commutation of Sentence, Pardon Application, etc.

4. Furlough: This is a temporary release of a prisoner for a specific purpose – usually a family event, to attend a funeral, or for a job interview. Necessary paperwork includes Request for Temporary Release, Furlough Agreement, etc.

5. Early Release for Good Behavior: In some states, prisoners can be released earlier than their full sentence if they show good behavior in prison. Forms required can include a Good Conduct Time Credit form, Application for Conditional Release, etc.

6. Presidential Pardon: This is a right that the U.S. president has to forgive a person for a crime and eliminate the punishment. The individual who receives the pardon will no longer suffer any ramifications for their crime. The Department of Justice oversees the process and it requires the filing of a Petition for Pardon form.

7. Release to Supervision: Some prisoners are released into the community but under the supervision of a probation officer. Documents involved include a Release of Information Form, Supervised Release Agreement, etc.

These are typically administered and monitored by a parole board or a prison warden, and usually have stringent terms that if broken, could result in the individual going back to prison. The released person must agree and sign these forms before the release.

The government often releases prisoners for various reasons. Here are a few circumstances in which this could occur:

1. Completion of Sentence: The most common reason for a prisoner's release is that they have served their entire sentence and are free to reenter society.

2. Parole: Parole is another form of early release, in which a prisoner is allowed to serve the rest of their sentence in the community under supervision.

3. Good Behaviour: In some cases, a prisoner may be released early due to good behaviour or participation in rehabilitative programs. This is often used as an incentive to encourage positive change and growth among inmates.

4. Presidential or Governor's Pardon: In the United States, a president or governor can grant a pardon or commute a sentence, essentially ending it early.

5. Prison Overcrowding: Sometimes, in order to alleviate overcrowded prison conditions, non-violent or low-risk offenders may be released.

6. Compassionate Release: This type of release might occur if a prisoner is terminally ill or severely disabled, and it would serve no purpose or be inhumane to keep them incarcerated.

7. Legal Revisions or Appeals: If a law changes, or a case is appealed and won, an inmate could be released based on the new legal landscape.

8. COVID-19 Release: Due to the risk of spread of COVID-19 in prisons, some governments released non-violent offenders or those with short sentences remaining to mitigate the public health risk.

It should be noted that the terms of release may vary, and not all releases are absolute. Some may come with conditions such as probation, community service, or continued treatment for mental health or addiction issues.

1. Guantanamo Bay: Since the 9/11 attacks, the United States has been using the detention facility at Guantanamo Bay, Cuba, to hold terrorism suspects. Many of these detainees have been released over the years due to lack of evidence, international pressure or negotiations.

2. US Federal Prisons: American prisoners are released from federal prisons after serving their sentences or on parole. The United States has the highest number of incarcerated individuals in the world. However, the rate of recidivism is also high, with over two-thirds of released prisoners being re-arrested within three years of release.

3. Prison Reform Initiatives: Recent years have seen a push for prison reform in the U.S., with a focus on rehabilitation over punishment. These initiatives include early release for good behavior, education and work programs, and drug treatment programs. The 2018 First Step Act is one such initiative that has led to the release of many prisoners.

4. Pardon or Commutation: Occasionally, U.S. Presidents exercise their power of pardon or commutation to release prisoners. This usually happens in the final days of a president's term.

5. COVID-19 Pandemic: In response to the COVID-19 pandemic, many prisoners, especially those at high risk, were released from prisons across the United States to reduce the spread of the virus within the overcrowded prison system.

6. Bail and Pretrial Release: After an arrest, a person can often secure their release from detention through the payment of bail. If they fail to appear in court as required, they forfeit the amount paid. This system has been criticized for disproportionately affecting the poor, leading to ongoing efforts for bail reform.

The United States Constitution did not originally outlaw slavery when it was ratified in 1787. The original Constitution did not expressly mention slavery, but it contained provisions indirectly recognizing and accommodating it.

The Constitution had a provision (Three-Fifths Compromise) that counted slaves as three-fifths of a person for purposes of representation in Congress. Article 1, Section 2, Paragraph 3, stated: Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.

The Constitution also included a clause (Article 1, Section 9) prohibiting Congress from outlawing the importation of slaves until 1808: The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight...

The issue of slavery in America was settled only with the ratification of the Thirteenth Amendment in 1865, after the Civil War. The amendment declared: Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.