Here is the full list of all 28 1849 achievements.
The base game contains 18 achievements, and there is 1 DLC pack containing 10 achievements.
Build five California cities
Build three California cities
Build a town that attracts at least 100 residents.
Attract 50 residents to your town.
Accumulate $10,000 in cold hard cash
Build 10 California cities
Build 15 California cities
Build 20 California cities
Construct a sheriff, fire brigade, saloon, school, church and jail in the same town.
Build eight or more mines of any type on the same map.
Build 10 or more farms of any type on one map.
Build at least six breweries, distilleries or wineries on one map.
Build five or more hunting or logging camps on the same map.
Build a a city that attracts at least 200 residents.
Create a town that attracts at least 300 residents.
Stockpile 1,000 units of gold in your depot. Just in case you need it.
Complete the public office commission in the San Francisco scenario.
Complete the grand mansion commission in the San Francisco scenario.
Complete the Dayton scenario in Nevada
Complete the Washoe City scenario in Nevada
Complete the Silver City scenario in Nevada
Complete the Gold Hill scenario in Nevada
Complete the Virginia City scenario in Nevada
Complete the Carson City scenario in Nevada
Complete the Virginia and Truckee Railroad
Build the Nevada State Capitol
Complete the Governor quest in Carson City
Complete the deep mine in Carson City