Plaquemines Parish LA Rosalina Johnson Anderson OR Peter Louis Anderson

I am looking for relations of Rosalina Johnson Anderson, born in Plaquemines Parish, Louisiana and her husband, Peter Louis Anderson (Per Ludwig Anderson) born in Kalmar, Sweden. They were married about 1877-1878 and lived in Plaquemines Parish. Peter was a sailor and died aboard the SS Chalmette in June, 1900. Rosalina later lived with her daughter in Gretna, LA and died in 1929. Their son, George Frederick, was my grandfather.