Bear in mind that conditions in life and in your career positions can vary tremendously, so this is just a generalization and simply my own opinion.
I've found that training in civil engineering helps you understand much about the world, government responsibilities and a wide range of engineering fields. However, in daily life and in solving specific problems, I've found that the emphasis of mechanical engineering studies will be more likely to be applicable and useful and to overlap with other careers.
Again, this is my opinion and not meant to be a necessary fact in your particular life situations.
All engineering disciplines are related to solving today's problems to create a better tomorrow. Civil engineering does this by changing the earth around us: creating cities, structures, and transportation solutions to bring the world together and improve quality of life. Mechanical engineering has a HUGE variety and could do this in a number of ways: improving/installing utilities, creating cars and airplanes, creating medical devices, and much more.
If you are more concerned about income / employment benefits, I recommend you visit the US Bureau of Labor Statistics webpage. They have projection data on the long-term outlook for various engineering disciplines as well as average starting salaries. This can vary by region / industry, so you can also use websites like glassdoor.com and salary.com to help.
All the best!