How to configure stemming in Solr?

Question

I add to solr index: "American". When I search by "America" there is no results.

How should schema.xml be configured to get results?

current configuration:

<fieldType name="text" class="solr.TextField" positionIncrementGap="100">
            <analyzer type="index">
                <tokenizer class="solr.WhitespaceTokenizerFactory" />
                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true" />
                <filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
                <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="1" catenateNumbers="1" catenateAll="0" />
                <filter class="solr.LowerCaseFilterFactory" />
                <filter class="solr.EnglishPorterFilterFactory" protected="protwords.txt" />
                <filter class="solr.RemoveDuplicatesTokenFilterFactory" />
                <filter class="solr.PorterStemFilterFactory"/>
            </analyzer>
            <analyzer type="query">
                <tokenizer class="solr.WhitespaceTokenizerFactory" />
                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true" />
                <filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
                <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="0" catenateNumbers="0" catenateAll="0" />
                <filter class="solr.LowerCaseFilterFactory" />
                <filter class="solr.EnglishPorterFilterFactory" protected="protwords.txt" />
                <filter class="solr.RemoveDuplicatesTokenFilterFactory" />
                <filter class="solr.PorterStemFilterFactory"/>
            </analyzer>
        </fieldType>

Answer 1

Why would you have two stemmers?
Try removing EnglishPorterFilterFactory (deprecated) from both of your analyzer types, rebuild the index and then try whether search for American will yield America.

If that wont work, the other thing you can try is to remove both of your stemmer filters and add SnowballPorterFilterFactory with language="English" instead.