| LaBarge | 8 |
| Labrie | 182 183 |
| Lacock | 478 |
| Lacy | 438 |
| Ladeau | 464 |
| LaFond | 293 451 |
| LaFountain | 48 69 73 74 79 81 82 83 87 153 159 176 185 195 201 212 254 325 333 334 343 351 381 382 428 |
| Lahr | 459 |
| Lainer | 504 |
| Lake | 438 513 |
| LaMantia | 435 |
| Lambeff | 381 |
| Lambert | 392 405 409 411 |
| Lamphier | 4 49 |
| Lance | 434 |
| Landa | 33 325 333 382 |
| Landru | 3 47 48 57 58 60 156 279 310 381 382 384 500 513 |
| Landusky | 429 |
| Lane | 22 64 172 289 291 314 331 332 333 348 372 378 390 405 407 |
| Lang | 171 417 |
| Langley | 162 |
| Langman | 218 |
| Laniphere | 293 |
| Lansberry | 293 |
| Lapalm | 463 |
| Lapham | 463 |
| LaPoint | 239 |
| Laraway | 23 368 |
| LaRette | 509 |
| Larkin | 293 |
| LaRock | 80 381 513 |
| LaRocque | 33 34 69 73 159 271 332 333 334 335 382 |
| Larsen | 78 79 143 318 339 349 373 434 442 |
| Larson | 27 42 58 59 66 75 114 122 143 163 183 202 241 252 263 330 378 381 382 399 432 513 |
| Laschat | 335 348 416 |
| Latham | 143 |
| LaTray | 483 |
| Latton | 240 |
| Latty | 335 |
| Laughery | 269 270 |
| Laughlin | 275 |
| Launtz | 312 |
| Laux | 293 |
| Lavadure | 159 |
| LaVatta | 189 |
| Lawton | 67 |
| LeBrun | 218 505 |
| Lecktra | 307 |
| LeClair | 450 |
| LeClaire | 30 168 |
| Lee | 3 47 293 428 |
| Legg | 30 440 447 448 449 452 469 |
| Lehman | 293 301 |
| Lei | 185 |
| Leitermann | 314 |
| Lelek | 142 145 245 247 273 282 426 |
| Lemke | 22 264 |
| Leninger | 74 |
| Lenling | 105 381 382 |
| Lenning | 304 382 |
| Leonord | 47 |
| Lerohl | 276 |
| Leslie | 90 390 |
| Lettengarver | 162 335 336 348 382 420 |
| Letty | 119 |
| LeVelle | 159 |
| Lewellen | 293 |
| Lewis | 120 344 362 370 391 392 405 406 409 427 507 513 |
| Ley | 276 |
| Lias | 392 409 |
| Lichter | 190 |
| Liddell | 277 |
| Lieberg | 353 |
| Liggett | 293 |
| Light | 99 455 457 458 |
| Lightfield | 214 |
| Likarich | 293 |
| Lillard | 454 455 |
| Limpus | 146 |
| Lind | 381 402 406 |
| Lindberg | 342 361 371 |
| Lindsay | 328 |
| Lindsey | 371 |
| Lindstrand | 211 |
| Lindstrom | 22 246 247 248 277 |
| Lindstrum | 381 |
| Linendoll | 399 |
| Link | 19 20 30 189 190 259 378 379 380 382 421 434 435 436 471 506 |
| Linster | 289 |
| Lipke | 47 48 |
| Little | 230 382 |
| Littlefield | 293 |
| Livermore | 342 478 498 |
| Livingston | 402 481 |
| Logan | 11 |
| Logsdon | 178 |
| Lohmire | 428 |
| Lohse | 127 |
| Lokavitch | 47 |
| Lome | 69 |
| Londo | 336 |
| Lonergan | 293 425 |
| Lonergran | 415 |
| Long | 88 112 129 405 406 407 |
| Longfellow | 270 273 |
| Louda | 488 |
| Love | 307 |
| Lovesletten | 164 |
| Lovitt | 232 239 |
| Luabach | 293 |
| Lucas | 99 100 367 |
| Lucht | 480 489 499 |
| Lucier | 59 163 |
| Ludeman | 227 233 238 239 242 |
| Lukes | 479 |
| Luking | 494 |
| Lumsden | 293 |
| Lund | 114 227 276 292 335 369 391 407 408 418 419 420 449 513 |
| Lunn | 390 416 |
| Lute | 446 |
| Luton | 142 |
| Lutz | 4 |
| Lyda | 129 |
| Lyngholm | 241 |
| Lytle | 381 |
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