How could codfish be considered the first version of a protein bar

It has less amount of protein than protein bar.

Explanation:

Codfish is considered as the first version of a protein bar because it has less amount of protein as compared to the protein bar. Codfish has 15 grams of protein in 85 gram of codfish while on the other hand, protein bar has 25 grams of protein in 100 grams of protein bar so that's why codfish is considered as the first version of a protein bar.

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

b) the confederacy had to pay all union war expenses.