The following is a summary of acts which authorized boundary changes for Giles County.
- Private Acts of 1811, Chapter 13, stated that whereas some doubt exists about the boundary line run between Giles and Lincoln Counties as authorized by the 1809 Act creating Giles County, the line run and marked by the Commissioners appointed in that act is declared to be the boundary between the two Counties.
- Private Acts of 1827, Chapter 201, changed the line between Maury and Giles Counties so as to include all the lands belonging to John Andrews in Giles.
- Private Acts of 1836, Chapter 35 created Marshall County which included part of Giles County. It was provided in the act that nothing should be construed as preventing the Giles County Court from rendering judgements. It was also provided that should the citizens in the fraction of land that was to be taken from Giles County to make up part of Marshall County vote to become part of Marshall County prior to the holding of elections in other counties, then the territory that comes to Marshall county from Giles county should be stricken from the south part of the Lincoln fraction.
- Private Acts of 1840-41, Chapter 179, change the county line between Knox and Grainger Counties, a provision is included in the act that Giles County not be reduced by more than 625 square miles.
- Private Acts of 1849-50, Chapter 110, Section 2, altered the line between Lincoln and Giles Counties so that the land and residence of Thomas Collins would be included all in Giles County and the County surveyor would run and mark the line accordingly.
- Private Acts of 1853-54, Chapter 130, transferred the tract of land granted to Felix Carroll from Giles County to Lawrence County.
- Private Acts of 1867-68, Chapter 20, detached all the lands belonging to C. J. Dugger from Giles County and attached them to Maury County.
- Private Acts of 1868-69, Chapter 39, moved all the lands of W. H. Hagen, James W. Hagan, William Hagan, and Sinia Garner (all names spelled as the Act had them) from Giles County into Lawrence County.
- Private Acts of 1870 (3rd Ex. Sess.), Chapter 18, Section 5, changed the boundary between Lawrence and Giles so that the 90 acres belonging to Emery Hughes would be included in Lawrence County.
- Private Acts of 1877, Chapter 155, altered the boundary between Giles and Lawrence Counties so as to include all the lands of James Harwell, Thomas M. Kelley, Katherine Hughes, Elsia Scott, John M. Berry, and about 100 acres of A. J. Hannah from the 18th Civil District of Giles County in the 4th Civil District of Lawrence County.
- Private Acts of 1879, Chapter 21, moved the house and farms of James Perry, Mr. Pollis and D. W. Kincaid from Marshall County into Giles County. This Act was cited in the case of Wilson v. State, 143 Tenn. 68, 224 S.W. 172 (1920), relative to the procedures of enactment rather than the contents of the Bill.
- Private Acts of 1879, Chapter 57, amended the June 30, 1870 Act by changing the boundary line so as to throw all the lands of W. T. Marsh into Marshall County, the boundary line for Marshall County, the boundary line for Marshall being run on the south border of this land instead of the north.
- Private Acts of 1879, Chapter 137, transferred all the lands of Berry Brashears from Giles County into the 9th Civil District of Lawrence County.
- Private Acts of 1901, Chapter 256, moved the lands of J. L. Ball, as described in the Act, from Lawrence County into Giles County.
- Private Acts of 1901, Chapter 308, detached the properties of T. M. Burgess, N. M. Smith, M. L. Burgess, W. N. Poarch, T. L. Poarch, James Gosnell, Mrs. S. J. Harris, and Mrs. Emma Moore from Giles County and attached all of them to Marshall County.
- Private Acts of 1905, Chapter 28, changed the lines between Giles and Marshall so as to place the lands of J. D. Cainer, and J. B. Smithson in Marshall County.
- Private Acts of 1909, Chapter 101, transferred the land of Howard Fox from the 17th Civil District of Giles County to the 4th Civil District of Marshall County.
- Private Acts of 1915, Chapter 384, attempted to add a strip of Giles County to Marshall County. This act, however, was declared unconstitutional in the case of Giles County v. Marshall County, 133 Tenn. 415, 181 S.W. 308 (1915), because the Marshall County line would then be within the eleven mile limit of the Giles County Seat, which is prohibited by the Constitution.
- Private Acts of 1925, Chapter 640, moved ten acres of land belonging to G. W. Stallings from the 4th Civil District of Marshall County to the 15th Civil District of Giles County.