Prior to the invention of the Westinghouse air brake in 1869 shortly after the Civil War, the brakeman's job was a miserable and dangerous one, while being constantly exposed to the elements when on duty.

Notice the long metal vertical rod operated by a handlebar on the back of the third car from the left which actuated the brake mechanisms on the trucks. Each car had to have its brakes adjusted manually by the brakeman sitting on the roof.

The third car clearly shows there's a footrest for the brakeman and directly to the right and slightly below is an open window where the foreman may shout orders at him.
Such luxuries!

Notice also the coupler system in this photo prior to the invention of the Janney spring-loaded coupler of 1874.
Look at those big square holes you had to load with big iron pins to tie the cars together.

Many opportunities to lose a limb or just get squished altogether, which happened often.

Sorry Dave - my picture source was dated wrong. My knowledge of your Civil War needs work. Guess the only thing I got right was both pictures have trains in them.

[Confusion probably stems from the fact that 1866 is the year the folio of photographs including the image below was published, not when the pictures were taken. - Dave]

A rather tranquil scene with the man taking his ease on the boxcar roof. The raw logs under the rails are in sharp contrast to the sleepers of today. But two years on all was to change.

[This isn't "two years on" -- both photos (which show different roundhouses) were made late in 1864. - Dave]

They had a more obvious idea of how a switch had to work.