Calcasieu Parish was created in 1840 from St. Landry Parish. The thing to remember is that our ancestors did not move - only the parish boundaries moved. Early church and civil records can be found in Southwest Louisiana Records by Rev. Donald J. Hébert. Before he died, Fr. Hébert published 41 volumes of SWLR beginning with the year 1750 and ending with the year 1909. To see a copy of Fr. Hébert's obit. go to hebertpublications.com
Calcasieu Parish, P.O. Box 1030, Lake Charles, LA 70602-1030 Telephone: 318-437-3550 Parish clerk has mar, div, civ ct & lnd rec from 1913.
Note: "The particular problem of missing records arose when certain churches suffered the loss of their records because of fires, etc. The area of LAKE CHARLES in particular felt this loss as the fire of 1910 destroyed the CIVIL RECORDS as well as the Catholic Church records."
My maternal grandmother,Adelaide Simon Fontenot, had first married in 1887 in St, Landry Parish, Arthur Erange Sonnier, who died in 1899. Adelaide married her second husband, Villeneuve LeDoux in 1901 also in St. Landry Parish. I searched everywhere for her in 1900 and finally found her in Calcasieu Parish at Hickory Flat. Apparently her property was located in the area that went to Calcasieu Parish.
From the information you provided, I would think that the census is the best place to look for your Lake Charles Ancestors. Most libraries have a subscription to Ancestry.com that includes the census. Ask your librarian for help.