neers, with the volunteer engineers, had during to fortifying all the important points on the railKentucky, while Lieutenant Colonel Simpson, d Cincinnati, Ohio, Covington and Newport, cky, and the lines of the Louisville, Nashville, thus covering Thomas's rear and defending his he labors of the engineers in Tennessee. y of the West under Sherman (see plan No. 3) nsive fortifications. Captain Poe, (brevet brigadier general U. S. A.,) general U. S. A.,) Lieutenant Stickney, (brevet dlow, (brevet major U. S. A.,) and Lieutenant usly bestowed upon the roads and bridges, and ments and positions. (See annexed narratives.) arge of these officers were indispensable to the sisted of canvas boats, which proved serviceafrom the Tennessee to its final disbandment in e advantages of these light trains, their frequent g their adaptation to our country, are fully ded from Poe's and Reese's reports. le was captured by our force, and in November vas occupied by our army. At the latter point lies, and moved in force against the rebels, drivnel Hill, Dalton, Resaca, Allatoona, and Kene army was strongly intrenched. The place was he north and east, when its strength being fully his army to the south, defeating the rebels at investing it on the south and compelling Hood to ed from the report of Brevet Brigadier General engineers, gives the important incidents connishes plans of the rebel defences. (See plan successes of the armies under Thomas and SherGrant ordered a division of his army under Gene navy in the reduction of the defences of the nuary, 1865. orps of engineers, (lieutenant colonel, A. D. C., eers,) had charge of the engineer operations of commanding the northern entrance of this river, position. Plans Nos. 5 and 6 give the details our army to cover its landing and its rear while resulting in dismounting many of the guns on well as cutting the electric wires for exploding the same front, preceded a successful assault erry. .5 and 6, with extracts from General Comstock's ! troops. (See General Comstoc Blakely (see plan No. 7) was Plan No. 7, with extracts from of the operations, final assault a April. 1865. (See McAlester's Spanish Fort was at the same The fall of Blakely and Spa Plan No. 9 gives the formid The determination of the co (See plan No. 3.) Sherman's in the season General Canby concentrated the troops under his command ved to the attack of the city of Mobile, having the co-operation of the The labors of the engineers under Captain McAlester, (brevet major U. Captain Palfrey, (brevet lieutenant colonel U. S. A.,) Lieutenant Burnrevet major U. S. A.,) and others, were here called into requisition. ely (see plan No. 7) was invested, batteries constructed and opened upon nidable rebel batteries covered by strong intrenchments, with abatis surg their entire position, with its flanks resting on the Blakely river. No. 7, with extracts from the report of Major McAlester, gives the details perations, final assault and construction of the rebel defences on the 8th 1865. (See McAlester's report, annexed.) ish Fort was at the same time invested by our army, and the more forsiege operations of a first and second parallel with approaches and enbatteries became necessary, and resulted finally in the capture of the fences by assault, on the 8th and 9th of April, 1865. (See plan No. 8.) e defences and approaches are given in detail on plans Nos. 7 and S. with extracts from Major McAlester's report, will explain and illustrate ll-designed and skilfully executed siege. fall of Blakely and Spanish Fort caused the rebel army under Taylor, r, and Maury, to evacuate Mobile, and retreat to the North. No. 9 gives the formidable rebel defences of the city of Mobile, surg it with three lines of detached forts and connecting intrenchments, e flanks resting on Mobile river. The skilful labors of the rebel engi bout this city were very extensive and the system exceedingly strong. determination of the commanding general to turn these works, by first g Blakely and Spanish Fort proved successful, and the character of the as shown on the plan forcibly illustrates the saving of lives and treasure first attempting to reduce these powerful defences. No. 10 gives the position of the entire and connected system of rebel s that succumbed to the skill and talent of Canby. le these important operations were in progress in Tennessee and Alabama, un, with the grand army of the West, and Lieutenant General Grant, with abined armies of the Potomac and the James, together with the garrison hington city, were simultaneously leading the national forces to strike a ow to rebel power, and enforce the restoration of national authority from antic to the Pacific. plan No. 3.) Sherman's army reached the sea-coast, by first capturing cAllister, on the 13th December, 1864, by Hazen. The strong rebel innents at Savannah were then invested, and the rebel General Hardee driven em across the Savannah river. The department has as yet received no f Fort McAllister or of the defences of Savannah. The labors of the rs of Sherman's army (see Poe's narrative) were again bestowed princi n reconnoitring the enemy's positions, and manoeuvring the canvas 1 trains to cross the army over the several rivers between Savannah and water-course crossed in pursuit of rebels. The success of these bridge s given in the extracts from Generals Poe's and Reese's reports. The Charleston fell into our power on the 18th February, 1865, after its ion by the rebels in consequence of Sherman's movements in its rear, ing off its supplies from the interior, while it was already blockaded by t, and invested by land by our army. field, after the reduction of the entire defences of Smithville, moved upon , and united his forces with those of Sherman. The engineer operations er Lieutenant Stickney, (brevet major U. S. A.,) Stickney's narrative.) After obstinately conh and Bentonville, the rebel power under Johnabdued by the capture of his entire command hich, by easy marches, the grand army of the y. -) The momentous campaign of the armies unnt General, with the purpose of capturing Richel authorities holding the semblance of Confedemmenced on the Rapidan in May, 1864. The 7th May; of Spottsylvania, on the 14th and Anna, on the 24th; of Coal Arbor, on the 31st hence and passage of the James river on the vestment of Petersburg on the 3d July, 1864, and battles and manoeuvres that do not come rts. formation from the report of Colonel Michler, specifically the labors of the officers of the enof this campaign. T AND LAKE DEFENCES. the corps of engineers have been actively enstated, others have given their attention to the nces. is of rebel cruisers and iron-armored vessels, be neutral, it was necessary to construct battesmooth-bored ordnance of heavier calibres than nb, Major Blunt, Major Casey, of the corps of us fortifying thirteen harbors on the eastern ss on the permanent sea-coast defences was conine to Hampton roads, inclusive, at Key West isco; and repairing the permanent works on the from the rebels, which had been more or less acks, to restore them to the Union. On the lso on the California coast, the main object has is soonest to mount the contemplated armaments, to be of such penetrating and crushing power he destruction of any iron-armored vessels that tion of these increased calibres and this power y to renew most of the gun platforms heretofore for no larger calibre than forty-two pounders. gun is prepared for the sea-coast batteries than and ten to fifteen inch rifled and smooth-bored e sea-coast batteries has been retarded by the o covering part of our guns and gunners as to advantage that an attacking power in ironhall possess. So far as we have yet progressed, libre have been perfected, and the guns mounted ed and forty-seven thousand one hundred and discharge, which is an addition during the year nd fifty-one pounds of metal that can be so SURVEYS, The surveys for the armies The survey of the northwester e power to overcome, and, in combination with other auxinary means of will carry the cost and time requisite to subdue them beyond the means gn powers, provided we hold our works in a perfect condition for both d sea attacks. ds of engineers have been detailed to consider what modifications are ry at each and every work along our sea-coast to adapt them to resist verful armaments that European fleets, singly or combined, may be to bring across the Atlantic, over the bars of our ports and harbors, to hem. details of the operations during the year at the several works on the c, Gulf of Mexico, Lake and Pacific coasts, derived mostly from the rethe superintending engineers, are annexed. PRISON DEPOTS. prison depots also called for the labors of engineer officers. Point t, at the mouth of the Potomac, was subject to sudden attack from mag parties and detached cavalry from armies operating against Baltimore ashington, which, with the immense body of prisoners, made it necesfortify the position against attempts to liberate them, by forts commandth the interior and exterior. Major Stewart, assisted by Lieutenant ll, and afterwards Colonel Brewerton, constructed these defensive THE PRISON DEPOT AT JOHNSON'S ISLAND, -eland harbor, Lake Erie, had to be defended against attempts of the ers, and succor by water, from expeditions organized in the friendly and I territories of Great Britain in Canada. Major Casey and Captain were assigned to and performed this service, constructing a water at the mouth of the harbor, against a force approaching by water, and ary field forts on Johnson's island. SURVEYS, MAPS, AND TOPOGRAPHY. surveys for the armies in the field, embracing the topography of the y passed over and particular sites occupied, have been referred to in parts of this report. extent of the labors performed by the officers on duty in the bureau en the engraving, lithographing, photographing and issuing 24,591 sheets icers in the field and various branches of the service requiring this infor, leaving still on hand a few copies of each publication for reference and Is of the War Department. survey of the northwestern lakes has been in progress for several years, in for the commerce of the States whose industry is promoted by that ed interior navigation the safety that a perfect and correct knowledge shores and bottom alone can attain. It is being conducted under the on of Major Raynolds, of the corps of engineers, upon the same scientific les and with the same care and accuracy that has been bestowed upon ast survey and other national geodetic surveys. During the year two have been prepared from the field-notes published and issued to the Lake Michigan. Three others have been pregraving, giving the Portage river and the bay id a third giving the north end of Green bay. enty (2,820) sheets of the maps of the lake. mmercial, harbor improvement, and military g the whole number of maps called for and ommenced 27,411 sheets. made during the year, maps issued and fornent, of Niagara river, Erie, Conneaut, Ashtack river, Sandusky, St. Joseph's, Grand Ha gan. SURVEYS. ties engaged in these surveys during the year nt of 2693 miles of shore-line, 164 square of soundings, and 1,200 square miles of offs of lines of soundings, the measurement of a h, difference of longitude between several disus, and observations by flashing lights; also latitude of eight points. eys are called for by numerous parties and rcial men, for private as well as for public use. s and system be established to keep the issue ch limits as will insure the great objects of the rmation to promote national industry, at the into the hands of persons collecting for other ent be therefore authorized to issue these maps, government, at the cost of paper and printing, -en authorized for distributing the Coast Survey roper use, and enable all persons capable of he work for the next year is $184,604 42, riated for last year s operations about $60,000. crease of estimate does not contemplate any is, but is simply due to the increased cost of illiamson, of the corps of engineers, has exf northern California and southern Oregon, Is, and continues observations for barometric so in view an investigation of the formula for rument. He has traversed and explored the Orthern California, said to be 10,000 to 11,000 d the military roads between the coast and ate the military operations of the commanding o examined the various sites on Admiralty ht hereafter become useful for military purd be reserved from sale by the land office. OF ATLANTIC HARBORS AND SEA-WALLS. 1864 for renewing the construction of the serve the head-lands from further destruction པY use, while at the same time it pr occupied by batteries bearing on following narratives of the operat of Colonel Graham, the superinte with the application of the appro repair of the harbors on the Atla views on this subject in relation Grace, dredging the Patapsco riv the Hudson river below Troy, a commends additional appropriati REPAIRS OF SEA-WALLS ON DEEE Deer Island sea-wall.—The w the north wall, middle wall, and 383 feet in length. There were six places averagin and flagstones of the platform blocks of stone had been forced In September, 1864, a viole clay backing from the north wal one of 300 feet in length, besides of the wall into the sea, and bul ward, which weakened it so n another such shock. No time portion and coramencing the r ment. Ninety feet lineal were ing season. Much damage was During the summer to the clo were taken down and rebuilt. work; and the estimate of the en Sea-wa'l on Lorell's island.— end of the island from abrasion The smallness of the appropriat on this and Deer island rendere than to procure the materials f on the work. The estimated cost of repairing SEA-WALLS AT GREAT B There are two walls, 372 and During the winter a large nu About $20,000 of the appropri The engineer in charge estima the continuance of this work, to |