It took over 40 days before the standoff at the Malheur National Wildlife Refuge in the city of Burns, Oregon came to a close, and it was made possible through the help of American evangelist Reverend Franklin Graham.

He, together with a Nevada lawmaker, helped negotiate on Thursday the surrender of the last four remaining holdouts who refused to be "a slave to this system," according to the New York Times.

"Thanking God that the ‪#‎Oregonstandoff is over and all are safe. After many hours of talks, Sean and Sandy Anderson, Jeff Banta, & David Fry all came out peacefully – and I'm very grateful," Graham wrote on his Facebook page.  "I know their family members are extremely relieved. This is a complicated controversy with the government that has roots going back many years. Praying that now their grievances will be heard and addressed through the right channels."

Graham said he spent several hours on the phone with the four men involved in the standoff, and he is happy that he "was able to have prayer with them."

The visit to Burns temporarily halted Graham's planned 50-state political and prayer rally tour called "Decision America," where he hosts a gathering at each statehouse and calls on Christians to consider their spirituality when voting in the 2016 elections.

Graham, a father of four and grandfather of 10, is the president and CEO of the Billy Graham Evangelistic Association as well as an international relief organisation called Samaritan's Purse.

After his arrival at the refuge, three remaining occupiers surrendered to the FBI. After a time, the last holdout, David Fry, also gave himself up, ending the 41-day standoff.

At least 16 occupiers —including leader Ammon Bundy — have been arrested. One man, their spokesman Robert "LaVoy" Finicum, was killed by state police when they attempted to arrest him.