[I am presuming that Corporal Frazee was discharged from the 19th Indiana Infantry Regiment before this time because he enlisted in the 100th Indiana Infantry Regiment on 28 Aug 1862. The 19th Indiana Infantry continued its military campaigns with the Army of the Potomac around Washington, D.C. While the 100th Indiana Infantry was assinged to the Army of Tennessee with General Grant.]

[The 19th Indiana Infantry Regiment] then joined Gen. Pope's Army, fought at Cedar mountain, Gainesville and the second Bull Run. At Gainesville it lost 187 in killed and wounded and 33 missing. After the second battle of Bull Run it was stationed for a time at Washington, then moved to Frederick City, Md., and when Lee began his invasion of Maryland moved with Hooker's corps in pursuit. At South mountain the regiment lost 40 in killed and wounded and 7 missing, and at Antietam went into action with 200 officers and men, of whom but 37 returned from the field. Col. Meredith was made a brigadier-general on Oct. 6, and Lieut. Col. Williams became colonel. At Fredericksburg the regiment was in the 4th brigade, 1st division, 1st corps, but was only slightly engaged. It then went into winter quarters until the beginning of Gen. Hooker's Chancellorsville campaign, when it was in an engagement at Fitzhugh's crossing of the Rappahannock, where it lost 4 men killed and wounded. It was in position at Chancellorsville, but was not called into action. It was then attached to the 1st brigade, 1st division, 1st corps, which was the first of the infantry to engage the enemy at Gettysburg on July 1, 1863. The regiment aided in the capture of Archer's Confederate brigade, but lost 210 men out of 288 that went into battle on that first day. During the other two days of the fight it occupied a position on Cemetery hill, but was not seriously engaged. It then took part in the Mine Run campaign and passed the winter near Culpeper, where a portion of the regiment reenlisted. It broke camp at the beginning of the Wilderness campaign; was engaged at the Wilderness, Laurel hill, about Spottsylvania, at the North Anna river and Cold Harbor; and was then constantly on duty in the trenches before Petersburg until the end of the siege. Its losses from May 4 to July 30, 1864, were 36 killed, 168 wounded and 16 missing. The non- veterans were mustered out at Indianapolis early in Aug., 1864, and the veterans and recruits as part of the "Iron brigade" took part in the expedition against the Weldon railroad. On Oct. 18, 1864, the regiment was consolidated with the 20th Ind., Col. Orr of the 19th becoming colonel of the new organization, and served thus until mustered out at Louisville, Ky., July 12, 1865.

The Roster of the Reorganized 20th Regiment Indiana Infantry does not include Isaac Newton Frazee. I don't find any records indicating him being transferred out of the 19th Regiment Indiana Infantry.

This regiment was organized at Lafayette in July 1861, and was mustered in at Indianapolis, July 22. It left the state on Aug. 2, being ordered to Cockeysville, Md., for railroad guard duty. It sailed for Hatteras inlet, N. C, Sept. 24, and was sent to north end of Hatteras bank, 40 miles from the fortifications, without transportation or artillery. It was attacked on Oct. 4, by the enemy's fleet, loaded with infantry, and was compelled to retreat. It embarked Nov. 9, for Fortress Monroe, where it remained until March, 1862. It was at Newport News during the engagement between the Merrimac, Cumberland and Congress, and prevented the enemy from taking possession of the Congress after she had struck her colors. It participated in the capture of Norfolk, and on June 8, was assigned to Jameson's brigade, Kearny's division, Heintzelman's corps, with which it fought at Fair Oaks. It was in the battle of Oak Grove, where it lost 144 in killed, wounded and missing, and covered the rear of the 3d corps in the Seven Days' battles, participating in all of them and being heavily engaged at Frazier's farm. It then moved to Yorktown, Alexandria, and thence to Manassas, where it was engaged, Col. Brown being killed. It was also in the battle of Chantilly, after which its division was ordered to rest, having lost heavily in its campaigns, and the 20th went into camp at Arlington heights. On Oct. 11, it crossed the Potomac, hoping to intercept Stuart's cavalry, and was in camp at Poolesville, Md., until Oct. 29, when it moved to Leesburg and Warrenton. With Franklin's corps it was engaged at Fredericksburg, and in May 1863, was in the battle of Chancellorsville, capturing the entire 23d Georgia, which outnumbered it, and when the 11th corps broke and the enemy turned the right of the Union forces, cutting off the 3d corps from the main army, the regiment made a bayonet charge, reestablishing communication. It pursued Lee through Maryland and Pennsylvania, reaching Gettysburg in time to participate in the second day's battle, where it was exposed to a sweeping fire, and lost 152 in killed and wounded, including Col. Wheeler. It was in hot engagements on the 3d, and in heavy skirmishing on the 4th. Overtaking Lee's rear-guard at Manassas gap, it aided in an attack and defeat of the enemy, and was then sent to New York during the draft riots. It was engaged at Locust Grove and Mine run in November. A portion of the regiment reenlisted as veterans on Jan. 1, 1864, at Culpeper and received a furlough. The 20th participated in the battles of the Wilderness, Todd's tavern, Po river, Spottsylvania, Totopotomy and Cold Harbor. At the last point the veterans and recruits of the 14th were consolidated with the 20th. It was engaged at Deep Bottom and Strawberry Plains, and was then in the trenches before Petersburg, under fire daily, Lieut. Col. Meikel being killed. On Oct. 18, the recruits and veterans of the 17th and 19th were consolidated with the 20th. The regiment was engaged in the various movements about Petersburg, participating at Peebles' farm, and Hatcher's run. It was in the advance division of the 2nd corps in the pursuit of Lee and participated in the various battles up to his surrender. It then moved to Washington, thence to Louisville, and was mustered out July 12, 1865. The original strength of the regiment was 1,051; gain by recruits, 410; reenlistments, 282; total, 1,743. Loss by death, 228; desertion, 66; unaccounted for, 176. On reorganization the strength was originally, 906; gain by recruits, 33; total, 939; loss by death, 44; unaccounted for, 56. See the history of the 20th Indiana Infantry. The unit also fought at the Battle of Gettysburg and in October, 1864, received the 19th Regiment Indiana Infantry. The 20th Indiana Infantry fought to the end of the war with General U.S. Grant and was present at the surrender of General Robert E. Lee at the Appomattox Court House.