Destroyer Squadron 21 in August 1943.
During World War II, as they commissioned and fleeted in, the 175 2,100-tonners were organized into nineteen squadrons (21–25 and 45–58), each with two divisions. Normally, a squadron was commanded by a captain who also commanded a division—commonly the lower-numbered one. Division composition could change rapidly, however, and divisions did not always operate together.

Initial or intended (e.g., where a ship was damaged before its squadron was formed) organization and initial or usual flagships were as follows:


DESRON 21

The first five 2,100-tonners from Bath and the first four from Federal.
DESDIV 41 — 449 Nicholas (flag), 450 O’Bannon, 451 Chevalier, 467 Strong, 468 Taylor.
DESDIV 42 — 445 Fletcher, 446 Radford, 447 Jenkins, 448 La Vallette.
681 Hopewell and 592 Howorth were initially assigned to replace Strong and Chevalier.

DESRON 22

The second four ships from Federal and from Bath plus one from Charleston Navy Yard originally fitted with a floatplane catapult.
DESDIV 43 — 465 Saufley, 466 Waller (flag), 477 Pringle, 498 Philip, 499 Renshaw.
DESDIV 44 — 507 Conway (flag), 508 Cony, 510 Eaton, 643 Sigourney.
469 De Haven, DesDiv 44’s intended flagship, was sunk before the squadron was formed.

DESRON 23

The first four ships from Orange, four more from Bath plus a second from Charleston Navy Yard intended for a floatplane catapult.
DESDIV 45 — 569 Aulick, 570 Charles Ausburne (later flag), 571 Claxton, 572 Dyson, 478 Stanly.
DESDIV 46 — 509 Converse, 511 Foote (initial flag), 512 Spence, 514 Thatcher.

DESRON 24

Three of the first four ships from Bethlehem, Staten Island (two high-bridge and one low-bridge), the last of four high-bridge ships from Puget Sound Navy Yard, the first four ships from Bethlehem, San Francisco (all low-bridge) and the last high-bridge ship from Boston Navy Yard (initially held for a floatplane catapult).
DESDIV 47 — 470 Bache, 471 Beale, 476 Hutchins (flag), 518 Brownson, 519 Daly.
DESDIV 48 — 526 Abner Read (flag), 527 Ammen, 528 Mullany, 529 Bush.
593 Killen was assigned to replace Brownson.

DESRON 25

The second four ships from Orange, the third four from Federal (three high-bridge; one low-bridge) and the third ship from Charleston Navy Yard (intended for a floatplane catapult).
DESDIV 49 — 479 Stevens, 573 Harrison, 574 John Rodgers (flag), 575 McKee, 576 Murray.
DESDIV 50 — 500 Ringgold, 501 Schroeder, 502 Sigsbee, 659 Dashiell.

DESRON 45

The first four ships from Boston Navy Yard and four from Bath plus one from Puget Sound Navy Yard that initially carried a floatplane catapult.
DESDIV 89 — 472 Guest, 473 Bennett, 474 Fullam (flag), 475 Hudson, 480 Halford.
DESDIV 90 — 513 Terry, 515 Anthony, 516 Wadsworth, 630 Braine.

DESRON 46

DESDIV 91 — 581 Charrette, 582 Conner, 587 Bell, 588 Burns, 589 Izard (flag).
DESDIV 92 — 544 Boyd, 545 Bradford, 546 Brown, 547 Cowell.

DESRON 47

DESDIV 93 — 530 Trathen, 531 Hazelwood, 532 Heermann, 533 Hoel, 534 McCord (flag).
DESDIV 94 — 554 Franks, 555 Haggard, 556 Hailey, 557 Johnston.

DESRON 48

DESDIV 95 — 517 Walker, 629 Abbot, 631 Erben (flag), 642 Hale, 644 Stembel.
DESDIV 96 — 660 Bullard, 661 Kidd, 666 Black, 667 Chauncey.

DESRON 49

DESDIV 97 — 577 Sproston, 578 Wickes, 579 William D. Porter, 580 Young, 685 Picking (flag).
DESDIV 98 — 520 Isherwood, 521 Kimberly, 522 Luce, 657 Charles J. Badger.

DESRON 50

DESDIV 99 — 668 Clarence K. Bronson (flag), 669 Cotten, 670 Dortch, 671 Gatling, 672 Healy.
DESDIV 100 — 650 Caperton, 651 Cogswell, 652 Ingersoll, 653 Knapp.

DESRON 51

DESDIV 101 — 583 Hall (flag), 584 Halligan, 585 Haraden, 590 Paul Hamilton, 591 Twiggs.
DESDIV 102 — 550 Capps, 551 David W. Taylor, 552 Evans, 553 John D. Henley.

DESRON 52

DESDIV 103 — 535 Miller, 536 Owen (flag), 537 The Sullivans, 538 Stephen Potter, 539 Tingey.
DESDIV 104 — 673 Hickox, 674 Hunt, 675 Lewis Hancock, 676 Marshall.

DESRON 53

DESDIV 105 — 658 Colahan (initial flag), 686 Halsey Powell (later flag), 687 Uhlmann, 796 Benham, 797 Cushing (final flag).
DESDIV 106 — 540 Twining, 541 Yarnall, 683 Stockham, 684 Wedderburn.

DESRON 54

DESDIV 107 — 678 McGowan, 680 Melvin, 688 Remey (flag), 690 Norman Scott, 691 Mertz.
DESDIV 108 — 677 McDermut, 679 McNair, 689 Wadleigh, 798 Monssen.

DESRON 55

DESDIV 109 — 682 Porterfield (flag), 792 Callaghan, 793 Cassin Young, 794 Irwin, 795 Preston.
DESDIV 110 — 558 Laws, 559 Longshaw, 560 Morrison, 561 Prichett.

DESRON 56

DESDIV 111 — 481 Leutze, 586 Newcomb (flag), 662 Bennion, 663 Heywood L. Edwards, 664 Richard P. Leary.
DESDIV 112 — 649 Albert W. Grant, 562 Robinson, 563 Ross, 665 Bryant.

DESRON 57

DESDIV 113 — 564 Rowe (flag), 565 Smalley, 566 Stoddard, 567 Watts, 568 Wren.
DESDIV 114 — 654 Bearss (flag), 655 John Hood, 799 Jarvis, 800 Porter.

DESRON 58

DESDIV 115 — 656 Van Valkenburgh (flag), 801 Colhoun, 802 Gregory, 803 Little, 804 Rooks.
DESDIV 116 — 594 Hart, 595 Metcalf, 596 Shields, 597 Wiley.