Eric Walker added "SSBN-X Future Follow-on Submarine" to Columbia-class submarine
Eric Walker added "Ohio Replacement Submarine" to Columbia-class submarine
Eric Walker added Columbia-class submarine - Wikipedia to Columbia-class submarine
Eric Walker updated the time prefix for Columbia-class submarine to be "2020"
Eric Walker updated the time prefix for Columbia-class submarine to be "2024"
Eric Walker added Columbia-class submarine to Nuclear-powered ballistic missile submarines