In modern times we have developed the notion that there is a correct spelling of a name. In prior times this kind thinking would be regarded as rather odd. We have birth certificates, social security cards and other documents that establish what our name is and its official spelling. Prior to the late Nineteenth Century none of these things existed. People spelled all words phonetically, names included. In many cases one can find different spellings of the same surname within a given document and in some cases by the same writer within that document. Dictionaries did exist giving suggested spellings for words. Samuel Johnson's Dictionary of the English Language was published in 1755 in England and Noah Webster's The American Spelling Book appeared in 1788. However, most people did not own these books and the spelling advocated by the authors of dictionaries often failed to make the cut. For example, Webster believed tongue should be spelled "tung." The problem with English is that there is no absolute recognized authority for English spelling, grammar or pronunciation, such as one finds for some foreign languages, e.g. French. As a result dictionaries are only the opinions of the editors and the English language continues to evolve in a very democratic way. In fact, the language has changed so much over time that the spoken English of the original Canterbury Tales written by Chaucer 600 years ago might be mistaken by a modern listener to be something read in Swedish or some other foreign language.
The origin of the surname Lanham is generally attributed to the British Isles, but interestingly various Lanham families will claim England, Scotland or Ireland as the point of origin for their Lanham ancestors. DNA studies done on descendants support an origin in the British Isles, but are unable to prove a specific point of origin. Some surname reference books believes the name originated with the village of Langham (long hamlet) in Kent, England. An alternate is "Leana's Homestead' appearing in Eldon C. Smith's New Dictionary of American Family Names.
The spelling Lanham has been used in Maryland records from the earliest immigrants and the surname spelled Langham seems to have been used consistently by other families as a distinctly different name. Lanham is generally pronounced "Lan'um" not "Lan-ham" and as a result the alternate phonetic spelling Lanum is common in records. Other spellings include Lanam, Lannum, Lenham, Lannom. Interestingly enough in the southern United States some descendants of Maryland Lanhams evolved the name Lannom as the standard spelling of their surname.
Many of these spellings illustrate what is called h-dropping or a fragile "H" in linguistics. This is speech in which an "H" is dropped from pronunciation at the beginning of a word or syllable. For example, a Cockney might say, "'e is 'ere." It is likely that at one time the "H" was pronounced. The most educated persons writing the name Lanham in old Maryland records were the Anglican parish priests and with only one exception they used the spelling Lanham. This causes me to consider it the standard spelling. The Encyclopedia of American Family Names by Robb and Chester ranks Lanham was the 3469th most common surname in the United States.
Spelling variations also exist for given names. I generally have tried to keep the spelling that appeared in the original records.