There were 56 signatories to our Declaration of Independence, to which none of them had names that were more than three syllables, and while last names of one-to-three syllables are still common in the United States, they aren't as common as they use to be. Instead, you have names such as Warszawski, Mihhailov, Papadopoulos, Giordano, Kavaliauskas, Olajowon, Milosevic, Iglesais, Shevchenko, dos Santos Aveiro, and so forth. There was a time when Eastern European immigrants or other immigrants would anglicize their name, or abbreviate it, or simplify it basically to fit in more seamlessly with the mainstream of America. This would then make it easier for them to be identified more in a manner consistent to the American way of life, but this is far less likely to occur in the 21st century.
Shakespeare asked the question, "what's in a name," and for the most part the answer seems to be that other countries have certain traditions or naming conventions that necessitate the lengthening of surnames. For instance, in many countries patronyms or sometimes matronyms are the basis for the formulation of a given last name. Basically, a patronymic naming convention takes the name of the father and combines it in such a manner as to display the lineage of their family. So a name such as Kowalczyk means "Smith's son" and Jansons means "son of Janis". Another naming convention is a reflection of the trade of the father, so that Lakatos means "locksmith", and Schneider means "tailor". One's surname can also reflect the part of the country that you are from, such as Van Der Meer which means "from the lake".
Then there are countries that seem to just add on suffixes to names, such as "ski" or "owicz" which at one time might have signified that the person hailed from nobility, but today doesn't signify that at all, because surnames were often only given to nobility back in days of nobility and serfs, but as a middle class developed, the middle class gained surnames, which eventually found its way down to the common folk, and logically in order to identify ourselves, surnames were created that either displayed lineage, or a trade, or the township that the person was from.
In America, one of the naming conventions that has gained some traction over recent years is the combination of a two names into a combined or hyphenated last name, such as when two people get married, to which the last name will then become, for example, Hopkins-Wilson. In most Latin American countries it is common to have double surnames to which they are not hyphenated and for everyday usage only the first surname is used. The creation of a surname typically contains the father's first surname being used first and the mother's first surname being used second, so that when Pablo Sanchez Rodriguez has a child with Maria Garcia Lopez, their child's surname will be Sanchez Garcia.
Because America is such a melting pot, we have quite a variety in surnames, in their naming conventions, and in their traditions. The fact that people today have a tendency to maintain their surnames consistent to their heritage helps us to recognize that America is far more inclusive than it has ever been.