After the American Civil War, a group of Southerners left for Brazil — where the "Confederados" remained so culturally separate from the rest of Brazilians that to this day their ancestors speak in the cadences of South Georgia: A linguistic time capsule "preserved in aspic".
With "Confederates in the Jungle", Ron Soodalter has written a great piece about these Civil-War expatriates, and the curiously historical value of their language patterns:
One clear indicator of the fierceness with which the rebel settlers maintained their identity is in their speech. Despite five generations of assimilation, the English language has survived, perfect and intact, among a number of the bilingual Confederados. Amazingly, although most have not visited the United States, their speech clearly reflects that of the American South. When Jimmy Carter, then the governor of Georgia, visited Campo in 1972, he was stunned: "The most remarkable thing was, when they spoke they sounded just like people in South Georgia."
The Confederados represent a human treasure trove for modern-day linguists. Throughout the past century and a half, scholars have puzzled over what the Southerners of the Civil War era actually sounded like. The Brazilian descendants' English, in the words of one latter-day rebel, has been "preserved in aspic"; in its purist form, it stands virtually frozen in time, reflecting the pronunciations and speech patterns of their forebears, dating from the third quarter of the 19th century.
That photo above is two of the original Confederados, Joseph Whitaker and Isabel Norris. Go read the whole article — it's worth it!