com.microsoft.sqlserver.jdbc.SQLServerDriver not found error

I am trying to connect to my SQL Server 2008 database from Java and I'm having the same problem from this thread.

String userName = "xxxx";
String password = "xxxx";
String url = "jdbc:sqlserver:xxx.xxx.xxx.xxx;databaseName=asdfzxcvqwer;integratedSecurity=true";
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
connection = DriverManager.getConnection(url, userName, password);

I keep getting a ClassNotFoundException Whenever I try to load the driver from Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1713)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1558)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at repositories.RepositoryBase.<init>(RepositoryBase.java:22)
    at repositories.ProductsRepository.<init>(ProductsRepository.java:13)
    at api.Products.init(Products.java:31)
    at javax.servlet.GenericServlet.init(GenericServlet.java:160)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1193)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:865)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:136)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apac