- Kaczmarek 106
- Kahl 149
- Kahler 159
- Kahn 526
- Kain 121
- Kaiser 1177
- Kale 61
- Kalinowski 103
- Kamara 25
- Kaminski 482
- Kaminsky 106
- Kammerer 65
- Kamp 94
- Kane 1603
- Kang 376
- Kangas 114
- Kantor 101
- Kao 71
- Kaplan 1332
- Kapp 92
- Karas 117
- Karim 45
- Karnes 136
- Karns 80
- Karp 175
- Karr 271
- Kasper 330
- Kass 106
- Kasten 114
- Kastner 96
- Kates 45
- Kato 46
- Katz 1391
- Kauffman 769
- Kaufman 1363
- Kaufmann 217
- Kaur 20
- Kautz 85
- Kavanagh 159
- Kavanaugh 160
- Kaylor 121
- Kayser 74
- Kean 95
- Keane 378
- Kearney 646
- Kearns 492
- Keating 627
- Keaton 163
- Keck 348
- Kee 148
- Keefe 400
- Keefer 324
- Keegan 345
- Keel 154
- Keeler 319
- Keeley 121
- Keeling 190
- Keen 509
- Keenan 658
- Keene 519
- Keener 396
- Keeney 219
- Keeton 201
- Kehoe 243
- Keil 145
- Keim 160
- Keiser 237
- Keister 91
- Kell 112
- Kellam 65
- Kellar 79
- Kelleher 351
- Keller 3030
- Kellerman 68
- Kelley 3595
- Kellner 107
- Kellogg 469
- Kellum 80
- Kelly 5754
- Kelsey 375
- Kelso 183
- Kemp 1304
- Kemper 294
- Kempf 148
- Kendall 905
- Kendrick 664
- Kennard 68
- Kennedy 4412
- Kenner 68
- Kenney 905
- Kennon 74
- Kent 1343
- Kenyon 375
- Keough 127
- Kephart 115
- Kerby 73
- Kerley 90
- Kern 988
- Kerner 76
- Kerns 431
- Kerr 1471
- Kerrigan 169
- Kersey 173
- Kershaw 97
- Kershner 81
- Kerwin 124
- Kesler 149
- Kessel 93
- Kessinger 68
- Kessler 1093
- Kester 176
- Ketcham 81
- Ketchum 182
- Key 875
- Keyes 403
- Keys 371
- Keyser 230
- Khalil 41
- Khan 872
- Khoury 102
- Kibler 134
- Kidd 903
- Kidder 140
- Kidwell 224
- Kiefer 366
- Kieffer 197
- Kiel 123
- Kiernan 192
- Kiger 75
- Kight 91
- Kilburn 74
- Kilby 113
- Kile 114
- Kiley 186
- Kilgore 587
- Killen 72
- Killian 364
- Killingsworth 56
- Killion 100
- Kilmer 97
- Kilpatrick 327
- Kim 2687
- Kimball 685
- Kimble 371
- Kimbrell 114
- Kimbrough 226
- Kimmel 319
- Kimura 44
- Kinard 135
- Kincaid 470
- Kinder 234
- Kindle 70
- Kindred 81
- King 9121
- Kingery 91
- Kingsbury 170
- Kingsley 215
- Kingston 144
- Kinley 51
- Kinney 974
- Kinsella 134
- Kinser 90
- Kinsey 408
- Kipp 165
- Kirby 1652
- Kirchner 316
- Kirk 1572
- Kirkham 77
- Kirkland 807
- Kirkman 138
- Kirkpatrick 838
- Kirksey 70
- Kirkwood 175
- Kirsch 320
- Kirschner 123
- Kiser 555
- Kish 272
- Kiss 74
- Kissel 94
- Kissinger 129
- Kistler 157
- Kitchen 341
- Kitchens 235
- Kite 130
- Kittle 106
- Kittrell 81
- Kitts 90
- Kizer 98
- Klatt 103
- Klaus 137
- Klein 2953
- Kleinman 82
- Kline 1495
- Kling 203
- Klinger 295
- Klotz 160
- Klug 209
- Knapp 1347
- Knecht 172
- Knight 3574
- Knighten 35
- Knighton 71
- Knoll 318
- Knopp 94
- Knorr 103
- Knott 384
- Knotts 141
- Knowles 840
- Knowlton 198
- Knox 1231
- Knudsen 265
- Knudson 213
- Knuth 73
- Knutson 607
- Ko 163
- Kobayashi 32
- Koch 1741
- Kocher 194
- Koehler 690
- Koehn 256
- Koenig 890
- Koerner 146
- Koester 213
- Koger 56
- Kohl 305
- Kohler 570
- Kohn 295
- Kolar 115
- Kolb 428
- Koller 165
- Kong 112
- Koo 40
- Koon 114
- Koonce 105
- Koons 172
- Koontz 319
- Kopp 384
- Korn 166
- Kornegay 71
- Korte 127
- Koski 165
- Koss 140
- Koster 166
- Kovach 323
- Kovacs 290
- Koval 97
- Kowal 108
- Kowalczyk 140
- Kowalski 593
- Kozak 208
- Kozlowski 327
- Kraemer 278
- Kraft 773
- Krall 105
- Kramer 2248
- Krantz 171
- Kranz 136
- Kratz 139
- Kratzer 97
- Kraus 710
- Krause 1257
- Krauss 214
- Krebs 389
- Kreider 172
- Kremer 250
- Kress 211
- Krieg 121
- Krieger 369
- Kroeger 132
- Krohn 175
- Krol 90
- Kroll 386
- Kropp 90
- Krueger 1347
- Krug 282
- Kruger 449
- Krull 102
- Krupa 105
- Kruse 835
- Ku 40
- Kubiak 86
- Kucera 86
- Kuehl 135
- Kuehn 217
- Kugler 101
- Kuhl 159
- Kuhlman 213
- Kuhn 1131
- Kuhns 197
- Kulkarni 30
- Kulp 120
- Kumar 156
- Kunkel 328
- Kunkle 124
- Kuntz 421
- Kunz 319
- Kuo 118
- Kurth 119
- Kurtz 859
- Kurz 112
- Kushner 137
- Kutz 103
- Kuykendall 231
- Kwak 62
- Kwan 152
- Kwiatkowski 166
- Kwok 61
- Kwon 141
- Kwong 90
- Kyles 34
Lasnames By K