In his e-mails, Berg wrote of traveling to Diwaniya, about 110 miles south of Baghdad, to locate a radio tower to work on. Night had fallen, and while trying to negotiate with taxi drivers for a ride to Baghdad, Iraqi police stopped him.
"It seems they had reports about unknown Iranian people infiltrating their town, and at night they can't see much of my face," Berg wrote on Jan. 18. "The police collect me and take me off to the Lieutenant who is more worried for my safety than about me being an Iranian spy."
After explaining his story that night and the next morning he was allowed to leave.
The e-mails were shared with The Associated Press by David Skalish, a friend and colleague of Berg's who is an engineer for Philadelphia's WPHT-AM.
"Would that (the detention) have been a warning? Sure, I think so," Skalish said Wednesday. "But he was on a journey. In his mind it was a journey of a lifetime. He had a different comfort zone for the region."
In a Jan. 4 dispatch, Berg talks about working near Abu Ghraib.
"Then I'm back to Baghdad to hire our local business manager and hopefully get on two 1000' towers outside of Baghdad at Abu Ghreb (the site of a notorious prison for Army and political prisoners)," he wrote.
Berg's father, Michael, who opposes the war in Iraq, said top U.S. officials created an environment of limited civil rights that led to the abuses at Abu Ghraib.
"Nick died for the sins of the Bush administration," Michael Berg said Wednesday in an interview with The Associated Press.
Skalish said it was "uncanny" Berg would have been near the prison in January. "I read this a while back and you think, oh a prison. It's an afterthought. But now, oh my word," he said.
Berg traveled to Diwaniya, Mosul, Shomali and Sinjar in Iraq. But his most dangerous travel would have been around Abu Ghraib, which sits squarely in the Sunni Triangle.
In a likely nod to the dangers of solo travel for an American, Berg wrote that he found it handy to be confused as a Turk.
Other dispatches from Berg talk of a "wicked sand storm," encountering few people who could understand his elementary Arabic, and of the beautiful countryside.
Berg also surmises that the U.S.-enforced no-fly zones in Iraq from the 1990s led to hundreds of radio towers not having warning lights.
"Just last week a Coalition helicopter ran into a short utility tower in the North near Mosul, knocking out one of the main 400 kV lines," he wrote.
Berg's e-mails at times turned technical, writing he put under this banner: "WARNING TO CASUAL READERS, TECHNICAL STUFF AHEAD:"
"So anyhow, this massive tower is home to a cantilevered, on-air VHF antenna and a 6-1/8" flexible transmission line. That's it. No lights, no lightning arrester, no grounding, nothing else," he wrote.
Berg's body had been scheduled to land at Dover Air Force Base in Delaware on Wednesday, and officials gave conflicting accounts of whether the family had received permission to view the arrival.
Base spokesman Lt. Col. Jon Anderson said there was no outright prohibition on families' being present, but the office of Sen. Arlen Specter, R-Pa., said the Pentagon denied the family's request to witness the arrival.
In the e-mails, Nicholas Berg mentions meeting a brother of an uncle by marriage. Michael Berg said that his sister, who is now deceased, married an Iraqi man who lives near Baghdad.