Rifleman, attention!
Observe the following recruiting poster found in Maine in the summer and fall of 1861, during the early months of the War Between the States.

Retrieved from the Library of Congress, https://www.loc.gov/item/rbpe.02703700/. (Accessed January 09, 2018.)
Riflemen, ATTENTION!
A COMPANY OF ONE HUNDRED MEN to be selected from the BEST RIFLE SHOTS, In the State, is to be raised to act as a COMPANY OF SHARP SHOOTERS through the War. Each man will be entitled to A BOUNTY OF $22,00, When mustered into the service of the United States, and 100,00 DOLLARS at the close of the War, in addition to his regular pay.
No man will be accepted or mustered into service who is not an active and able-bodied man, and who cannot when firing at a rest at a distance of two hundred yards, put ten consecutive shots into a target the average distance not to exceed five inches from the centre of the bull’s eye to the centre of the ball; and all candidates will have to pass such an examination as to satisfy the recruiting officer of their fitness for enlistment in this corps.
Recruits having Rifles to which they are accustomed are requested to bring them to the place of rendezvous.
Recruits will be received by JAMES D. FESSENDEN, Adams Block, No. 23, Market Square, PORTLAND, Maine.
Sept. 16, 1861. Bridgton Reporter Press,—S. H. Noyes, Printer.
The above broadside, is, of course for Col. Hiram Berdan’s U.S. Sharpshooters. Tasked in 1861 with recruiting of 18 companies of marksmen, from 8 states, which were formed into two regiments (1st and 2nd U.S. Sharpshooters) later year. Company “D” of the 2nd USSS was raised in Maine on November 2, 1861.
Their distinctive green uniforms served them well until they were replaced with more standard Union blue by 1863.
When the Sharpshooter brigade was disbanded altogether in late 1864, the remaining Mainers of the company were rolled into the 17th Maine Volunteer Infantry Regiment and ultimately mustered out on June 10, 1865, after the Siege of Petersburg and the Appomatix Campaign.

Did they get the $100 on mustering out?
Yup. After 1863, when bounties typically went up, soldiers got 1/3 at muster, 1/3 halfway through the enlistment, and 1/3 when mustered out, but prior to that the federal $100 bounty was only paid after the enlistment was up. $11 per month was the regular pay for a private until 1863 when it went up to $13, making the bonus about 9 months’ worth.